Can you solve the bridge riddle? - Alex Gendler

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Taking that internship in a remote mountain lab might not have been the best idea. Pulling that lever with the skull symbol just to see what it did probably wasn’t so smart either. But now is not the time for regrets because you need to get away from these mutant zombies...fast. Can you use math to get you and your friends over the bridge before the zombies arrive? Alex Gendler shows how.
Lesson by Alex Gendler, animation by Artrake Studio.

[@Borednesss]

Well you don't have to cut the bridge.. it'll collapse from the zombies.

[@livdafish1165]

omg yas

[@jeremyvidaurri]

glad I wasn't the only one thinking about that.

[@jeremyvidaurri]

Heisenberg You seem to be misunderstanding him. Once everyone is over, there is no point in cutting the rope. The bridge would collapse anyways

[@GuillaumeRx]

+Jeremy Vidaurri They could pass one by one, it doesn't say Zombies can't think ahah

[@GuillaumeRx]

That matters because if they can, which isn't said, they really have to cut the bridge.

[@siddharthpanchal9474]

"The old professor takes 10 minutes and you have 17" Guess who's the newest member of the zombie crew

[@FACTOPEDIAN]

professor !!

[@dhineshkarthik6620]

lol

[@fenderfrontman]

HAHSHJD

[@Micahsaurus]

@@FACTOPEDIAN good job!

[@SingularPhasmid]

Now, who's next?

[@cherribomb3707]

I would probably spend the whole 17 minutes thinking how to cross the bridge 🤣

[@LizLuvsCupcakes]

I just kind of assume the professor has already worked this out and I just need to shut up, listen up, and not mess up.

[@Aussiesurti]

Step 1: tell the zombies one of them have green eyes. this will buy you enough time to cross the bridge regardless of what strategy you want to use as long as it's one hour.

[@mathguy37]

Well it’s the amount of days there are zombies

[@guroseurio1221]

Step 2: Get eaten because they are zombies

[@lyteandronic]

Step 3: Profit.

[@xandermadrid4366]

Step 4: save enough time to buy a zombie

[@shadowking6298]

Step 5: Find 5 intergalactic criminals stuck in 7 planets

[@inmyflopera729]

As soon as I heard that the professor takes 10 mins...... SACRIFICES HAVE TO BE MADE Lmao

[@mecthegreat92]

Word lml

[@talon310calif]

He lived a long life.

[@jollybee3432]

Hahaha I'M DED😂

[@bunkman64]

If you want to make an omelet, you have to break some eggs! (Jack Nicholson as the Joker in Batman).

[@marcsands7973]

He had to hold on to the ropes every step of the way. My take on it was that he didn't need the lamp if he had to do that lol

[@malsawmzualachhakchhuak380]

Plot twist: They all died while the Professor was doing the maths.

[@notinsideyourwalls]

*oof*

[@davidohaegbulam9988]

Underrated comment

[@255kx9]

the professor: *soo it’s gonna take us* Everyone: *HURY UP* *dies*

[@dwizzzzzzzz]

That was pretty good 😂

[@juliuscesargalanote994]

@Richard Zhang r/woooosh

[@nishika9094]

I'm so proud of myself for finally solving a TED-Ed riddle, and actually doing it on paper and thinking it out.

[@xiangmusha8994]

Damn good job I’m actually purely here for the story I need to try working it out next time

[@Gamer-zq5eb]

You deserve a like for that, good job!

[@babayaga3064]

Good job fellow Indian.

[@drmalfunction1349]

i aint got the time for that...

[@imaaa1139]

im proud of you too.

[@randomzergling]

This riddle is unironically has scared me more than any horror movie. The visuals and music is just so unsettling. I couldn't turn corners in fear of the zombies when I was younger.

[@olivialin7111]

Me too i was too terrified to get out of bed during night time!

[@sharissasterling3720]

Same, the riddle had me quaking

[@twinklingbyeol]

glad im not the only one who was genuinely scared after watching this riddle

[@DrOmni-fd6so]

Personally it was the music getting me on edge that scared me most

[@mariustan9275]

Same here. Whenever I would re-watch Ted Ed riddles I skipped this one out of fear. Now I' not as scared, but that music still unsettles me.

[@ThyStare]

And as you hand the lantern to the janitor and he and the professor vanish through the darkness crossing the bridge you hear the professor's voice shouting from a distant spot: "Did I say seventeen? sorry, I meant seven"

[@mrthanos2404]

This is the best comment I have ever read XD

[@nguyentin8949]

What in the world .... the zombie hac no head lol :))

[@CoolDude-cl4of]

What's truly hilarious is that he wouldn't have said it to save himself. Seven minutes means that he wouldn't make it across the bridge either. I have a feeling that the Janitor might not wait up for him, however.

[@coollman8619]

@@CoolDude-cl4of the janitor would still die

[@captainshado783]

@@coollman8619 nah he'd just ditch the professor in the middle and make a run for it lmfao

[@nadiabouk8712]

Ted Ed: “You can’t swing across-“ Me: “Oh yes I can”

[@yuricpark]

Me tarzan

[@yuricpark]

Me: Tarzan can do it, why cant i

[@jacksonhuang4266]

@Draco Granger-Snape And I'm honored to be your 2nd like of this comment :)

[@CheeseTheWhistle]

you're not Tarzan

[@tirshma260]

Lololol

[@emmie1210]

My teacher did this riddle, and there were so many unique answers Niamh: “Well they didn’t say you couldn’t sacrifice anyone…” Millie: “use the boast as a raft” Annie: “the professor stays on the other side with the lantern and knocks out the zombies with his cane, then walks across” Beth: “cut open the lantern, start a fire, and burn the zombies to a crisp.”

[@DiamondcatolicoB09]

They so smart

[@Titanic-wo6bq]

I like the thinking of Beth.

[@mathguy37]

Millie didn’t listen to the rules but the others… not intended but not wrong

[@ed_cmntonly]

I'm scared of Beth

[@potatoheadpokemario1931]

leave with the janitor and let the lab assistant and professor die, they made the zombies, they can deal with them

[@zynyie]

This is so nostalgic. I was a kid when I first watched it and I had nightmares but looking back, I’ve seen scarier lol. Thank you for a good riddle and my kid nightmare fuel.

[@CoolEdo]

i know like why did it scare me

[@pewdewpiebridge]

bro same i had nightmares

[@bilinmezlik3417]

i know right? especially the 4 minutes part O_O

[@zynyie]

FRRRR AND I WAS THINKING: BRO NOT EVEN I WOULD DO THAT AND I’M [REDACTED] YEARS OLD

[@suhas608]

hard to believe i’ve been watching ted videos for 7 years now

[@renzodelrosario3637]

Tell the zombies that at least one of them has green eyes

[@-khushlush]

OZO

[@amywang3890]

What the, Crazed fish cat?

[@ulyssesvercosa6196]

HAHAHAHAHAHAHHA

[@erinthedemonhog2090]

XD LOL

[@popn6189]

u don't have to... The dictator is zombie too.

[@RetroBerner]

1. Run across the bridge with the lab assistant. 2. Forget everyone else 3. Get laid for saving lab assistant.

[@wildboy2222]

Genius!

[@bhusu]

+Steve Martino best answer so far : v

[@Bram06]

+Steve Martino *PLOT TWIST* the lab assistant was actually in love with the janitor, which, you just killed

[@RetroBerner]

+Bram06 I'd "console" her :p

[@ebatatas]

and now we know you don't have friends

[@Marctheunstoppable]

why do the zombies actually look terrifying

[@skullmastergamer]

Cuz their zombies

[@haiuyennguyen80]

IK, BUT WHY ARE THEY'RE DETAILED?! ​@@skullmastergamer

[@chupacadabra5161]

The tense music doesn't help either

[@scoodybookypoo49733onbreak]

"And you're still stuck on the wrong side of the bridge" So you run across in the dang dark.

[@hansgunnoo5159]

And fall to to your death after stepping on a rotten plank you didn't see

[@scoodybookypoo49733onbreak]

@@hansgunnoo5159 I've already run across, I know where to jump. Plus, I'm too fast to fall.

[@hansgunnoo5159]

@@scoodybookypoo49733onbreak damn alright then, can't argue with that

[@vatnidd]

Why can't the professor work it out?

[@EspaTuLaFielD]

+Samuel Lo cause it would take 1 minute, making the solution impossible

[@vatnidd]

EspaTuLaFielD But I would take less time figuring it out?

[@EspaTuLaFielD]

its meant to be prep when it happens, you know it! :D

[@frankdantuono2594]

As Professor Farnsworth once famously said: I'm afraid were going to have to use... math! Also, this professor already used up some time figuring out how long till the zombies arrive :)

[@cassidyrodriguez3941]

I know a answer just carry the slowest oeople then you and the lab assistant run across

[@degrelleholt6314]

I figured it out myself. The problem was, it took me six minutes to figure it out! So me and the lab assistant went across first, kept running, and made a pact never to speak of this event again.

[@Raf1Gamer]

+Degrelle Holt aha

[@DaybreakPT]

You could've gone back for the janitor and still have 3 mins to spare you heartless monster. Leave the prof tho, he was old as fuck anyway and he made the problem in the first place, so he should deal with the consequences, I'd leave him there anyway since the 17 mins could easily been 16 or so since it was just an estimate, could've been just a few seconds off and the 2 people crossing the bridge would be fucked, it's just not worth the risk.

[@astrosloth0199]

But u didn't cut the bridge

[@Tombee2]

I laughed too hard at this

[@jaelen8265]

Lol you didn't even need to cut the bridge because the zombies are dumb as hell anyways, so they would probably go all at once, causing the bridge to fall lmao

[@flameshard8748]

The zombies In this riddle used to terrify me as a kid lol

[@himekaguya6476]

I’m still frightened although I’m 17 now 🥲

[@SapphireSorceress]

Haha me too

[@eloise3106]

SAME

[@infinityeternal4702]

you also have to account for the time taken by the people for the calculations needed

[@ngchorhong3174]

I find it absolutely HILARIOUS they had to remove befriend the zombies as an option just to shut the trolls up

[@PEARLOFFTHEH00K]

YES!! me too

[@MocaHere]

But you can still 1.Confirm you have green eyes 2.Ask the zombies to leave

[@gorneth8313]

@@MocaHere PLEASE THIS JOKE IS WAY TOO OVERUSED

[@CREEDO.]

you're cringe, i hope yk dat

[@pasiaangelo6442]

@@gorneth8313 I don't get it. What is the joke?

[@blaster5800]

Why the fuck do I need a lamp to walk on a damn linear bridge.

[@at_msatomic2004]

CUZ THERE ARE HOLES IN DA BRIDGE

[@spaghettiking653]

That wasn't part of the riddle. Besides, the bridge has ropes.

[@ninarotti6141]

It said they had to get across an *old* rope bridge. It's probably worn down with lots of holes in the planks. Plus it's night and they could barely see without the lantern.

[@LeonCoretz]

Let's assume the actors are blind for a moment. They can rub their foot on the step ahead to make sure there is a step to stand on.

[@mercenary-433]

if its an oil lamp, they make small explosions when thrown XD either boost the old bastard using it or just throw it at a zombie

[@bernardobertamini856]

I'm sure a lot of people must have already commented so but the solution in the video is not the only one. It also works if the Lab Assistant (instead of the Internship student) comes back with the lantern (I'm referring to this part of the solution: 2:37 )

[@Hassan-I]

Wait you're right!

[@goodstuff-hr9jn]

wait what? that works?

[@vegetalss4]

@@goodstuff-hr9jn yeah the two methods are more or less equivalent, both you and the lab assistent need to carry the lantern back across the bridge once, so switching the two doesn't change the final result. The general solution is: you+lab go across -> either you or lab go back -> janitor+prof go across -> the other of you or lab go back -> you and lab go across. Both cases involve 1 trip at your speed, one trip at professor speed and 3 trips at lab assistent speed.

[@todayisthedayofsalvation]

No it doesn’t, your one minute short, you have to all be on the other side when it reaches 17 minutes

[@Posby95]

@@todayisthedayofsalvation It does work. You and the lab assistant cross, and 2 minutes have elapsed. Then she goes back with the lantern, and 4 minutes have elapsed. The professor and the janitor cross, and 14 minutes have elapsed. You take the lantern and go back, and 15 minutes have elapsed. Finally, you and the assistant cross the bridge one final time, and the 17 minutes are up when you get to the other side.

[@uhh9364]

I can't be the only one who is kind of scared of this video. I've watched it for 5 years now and I still get an eerie feeling whenever I return...

[@jasoncheng3303]

Me too! Maybe the music?

[@hansgunnoo5159]

Yeah same makes me feel like a jumpscares about to pop up

[@zynyie]

SAMEE BRO, Probably since I watched this when I was littler and I was scared of it before lol

[@SapphireSorceress]

Same

[@TV-gn9li]

me too.

[@aDotFromTheFuture]

Yeah, the obvious answer is to not use the goddamn lamp. It's a fucking bridge with two rope rails on both sides, so you can't get lost, you can't fall... it's a pretty obvious thing to do.

[@franzzzzz250]

but you wouldn't know if the others have made it safely across, and If you go on the bridge while they're still on will cause the bridge to collapse

[@aDotFromTheFuture]

filipinofortunecookie Yes because it would be impossible for them to just yell that they are safely across... sarcasm. Besides, bridges like the one shown in the video, always wobble from side to side as someone is walking on it, so when the wobbling stops, they have crossed the bridge. Or just give the lantern to the ones who pass the bridge first, thus being able to see when they have crossed it.

[@luvablepimpstarz]

But what if there are incomplete parts on the bridge. If you can't see them you won't know to cross over and end up falling through.

[@aDotFromTheFuture]

BadApple The narrator never said anything about there being incomplete parts on the bridge, so we can conclude that the bridge is completely intact, thus my solution is still correct.

[@luvablepimpstarz]

+aDotFromTheFuture the narrator also says you need a lamp , the solution requires you to make allowance for the lamp. " any one crossing must either hold a the lantern or stay close to someone who does" so your solution can't not include it.

[@howdoyouspace5425]

My teacher showed this riddle to my class and half the kids were saying "SACRIFICE THE PROFESSOR!"

[@heyokaikaggen6288]

That's just silly, you might actually need the Professor for course credits, you should kill the janitor and the lab assistant instead.

[@charityledger5316]

same thing here bud

[@gav-ce5cm]

The professor is the reason why all this started

[@channelrandom2225]

Me too

[@lunamoon842]

Bruh those kids are not chad 🗿

[@enricozincani2384]

Solved this one, it was pretty easy compared to the others. Thank you for the great riddles

[@JonahWho]

this riddle scared me so much as a child

[@rinrxl]

fr, the idea and design of the zombies made me anxious 😥

[@TV-gn9li]

the same. I think a Jumpstart will pop up.

[@JonahWho]

@@TV-gn9li *jumpscare

[@Lun4812]

Why do they need to cut the ropes? The bridge can't support more than two zombies anyways.

[@ryderwashington4199]

+Luna But still a zombie can get across.

[@dewin1166]

+Ryder Washington they're zombies, Im pretty sure they won't reason the fact that the bridge can only support 2 people

[@ryderwashington4199]

DaTechDR But according to this situation they can.

[@ipadarmygrowtopia5500]

+Ryder Washington how...

[@josephcroeniangamer3727]

+iPadArmy growtopia because the ridle say so, those are the rules XD

[@HartyBiker]

Hold up, the professor made zombies with night vision... he's getting thrown off the cliff

[@thaiwood7528]

LoneW0lf11 the question before this riddle is how did they cross the bridge to get to the castle😂??

[@justicemay7874]

why tf did he make zombz in the first place just leave the professor

[@user-gh7ks6fs7f]

Lmao 🤣

[@evelyn-ff3ks]

lmao yes

[@gabygacha6609]

@@thaiwood7528 everyone was there before eachother

[@gogga6902]

“We have seventeen minutes before the zombies arrive” *_takes twenty years to calculate a plan_*

[@frankiebo3005]

Love how the zombies just fell in a clump

[@Isvoor]

"17 minutes before they get here... Hmm... give me some time to work this out... hmm... Yes, that's it! In this order, it takes exactly 17 minutes." "That's great but now the zombies are 16 minutes away." "Shit!"

[@TianoAnnunziata]

Isvoor ?

[@tomtom1501tm]

TianoPCGamer, as in it took him 1 minute to work it out so he has less time

[@TianoAnnunziata]

TheTeenMusician what

[@persondeadtoshame]

TianoPCGamer hello my bretherin

[@channel_B5]

Actually, no... you just start running with the hottie, and work out the solution on the way...

[@helloareyouokay9842]

When he said “Minimize the time wasted by the two slowest people” I thought so throw them into the river....I think something is wrong with my mind set 😂😂

[@IllyAwesome]

Lily Made me laugh 😂

[@jaydenmcevoy6760]

HaHaHa LOL

[@Traul1983]

And waste perfectly edible zombie bait?

[@CheeseTheWhistle]

These are everyday people, not the mafia or the russian mob... XD

[@isaacnewton7424]

That was dope

[@MANOFTIME]

Just carry the janitor and grandpa across one at a time while you carry them just make them hold the lantern, after you carry them both across just pop back for the lab assistant. Even if it takes you 3 min including rest stops, it should only take you 8 min total for them both then 1 min for running back for the assistant and 2 min for both of you to get to safety. So you can do this in about 11 min.

[@dogtroxity101_]

you cant carry them, the bridge supports two people max.

[@sebbicle1181]

@@dogtroxity101_ ?????

[@rizqidwiramadhan1515]

You can't do that since the bridge can only hold 2 people max since it's an old and weak bridge *1:09* but i see your point just carrying the professor and janitor so you can run faster and eventually reach the bridge in just 4 minutes

[@neonic6041]

@@dogtroxity101_ he said one at a time but id still consider this a trick

[@RandomPerson-sh9tu]

Carrying someone will slow them down, perhaps even more so than if they had just walked, you can't quantify time saved, but it's not the same because you're neglecting the extra weight

[@laughingatthesky7]

This riddle used to scare me The zombies and the music were so spooky but now it’s nostalgic

[@69op2gg1005ify0m]

You don't need to cut the bridge it only holds 2 ppl at the time anyway and theres like 10 zombies

[@rositarose7928]

i think the same thing

[@TheLio666]

thats smart you are right zombie don t think

[@69op2gg1005ify0m]

actually it would make them heavier because they would be bloated with maggots and puss

[@thundertoon1398]

Like he said, 10 zombies!

[@janniefeng1284]

True, you can use that idea in case if you don't have scissors with you. ;)

[@444fame_]

Teded: “Can you solve the-“ Me, without missing a beat: *_no_*

[@jedi_cat_l4976]

I sloved the problem. I am good at math.

[@florinmoldoveanu6116]

It took me like 2 mintues to solve, it's quite simple really if you figure out the time of a bridge crossing is given by the slowest person crossing it at a time

[@lucario4486]

Lol same

[@impoppy9145]

Literally my answer to every riddle ever. I would rather waste my time playing Minecraft

[@joanniebacus]

@@jedi_cat_l4976 Stop bragging.

[@user-gd9rb2mv9t]

Mr Gendler, thanks for your another great video. I really got in love with math riddles. Thank you!

[@SNKRS4real]

This is definitely the best riddle I’ve ever heard.

[@decreer4567]

I was thinking about just one person carrying the other person so get across and back for 5 minutes

[@chenli180]

lol me too

[@rashad5360]

Lol same here

[@madjoemak]

de'monster 456 that's a good idea 💡

[@zaks7]

and the person being carried will hold the lantern. :D

[@tristan_5895]

But then the person that is fastest will *DEFINETLY* slow down because he is carrying someone

[@steampunkastronaut7081]

It's so frightening to think that there is a moment where everybody but YOU is on the safe side... And the assistant must go to the danger zone to save YOU, the one who started all this mess. And you are *_standing in the darkness_* waiting over 12 MINUTES, hoping the assistant will come back...

[@Tirreg88]

there is a second solution where you let the assistant run back first and you run back with the lantern second. first solution 2,1,10,2,2 = 17; second solution 2,2,10,1,2

[@ashutoshmahapatra537]

@@Tirreg88 absolutely right!

[@mandy2917]

Ikr, imagine if the assistant just left you there

[@makeromaniagreatagain9697]

Don't forget that that mess is your fault and they might not come back because of that

[@blacjackdaniels200]

Watch the movie Judgement Night..Jeremy Piven was that guy

[@deathbyduo]

This video actually terrified me as a child 💀

[@strikingsarcophagus]

Me, a big brain boy: *Carries each person across and speedruns surviving in eight minutes.*

[@himekaguya6476]

The assistant is fast too, remember?

[@4mnesia__]

Me as an intellectual: carries the professor and goes back with the lantern then carries the others across

[@bethanycharlotte9668]

That's what I was thinking too!

[@elliethek9789]

That's what I thought too!

[@Chels0704]

Yeah me too

[@analeahbertubin4826]

same

[@mb2770]

Same

[@pantonfire]

If the professor can figure the eta of the zombies, he can figure this....

[@devanarayanababu1996]

haha..what a witty reply.

[@zeenotcreepy-justbored710]

congratulations your children just passed kindergarten

[@thatsawrap5235]

I want to thumbs up but 666 likes is the perfect number.

[@lunarkookie9185]

@David Yu That is a really good idea

[@ilikepie1906]

It’s called “can YOU solve this riddle” not “can the professor solve this riddle”

[@skallehild]

i remember watching this for the first time in sixth grade and, since then, ive always remembered this specific video because of how the music is so freaking good

[@HHowardBros]

I think about this all the time. The music there while you were explaining was haunting and suspensful

[@chrixtine733]

Me:*pulls a lever that obviously is deadly Also me: solves a whole riddle to get across the bridge

[@theterrorofdimensions1326]

Lol. So true.

[@zubairislam5924]

How do u get across? My teacher is torturing me.

[@DrRank]

Why do we even HAVE that lever?

[@chrixtine733]

Dr. Rank idk......

[@Olly07]

@@DrRank So that you have this riddle. Duh

[@BigManlyBoyCool]

How to beat the zombies: step one: dig 3 blocks down step two: place block above you step three: wait for the sun to rise step four: zombies burn in sunlight

[@spodreman7732]

alternative: plants some peashooters

[@gamerberry2451]

Man Of Culture. And oh, pick up the rotten flesh after.

[@spodreman7732]

Gamerberry You can’t do anything with the rotten flesh unless you have dogs, which you probably won’t have after the first night

[@gamerberry2451]

@@spodreman7732 food glorious food

[@spodreman7732]

Gamerberry But this food makes you hungry, making it the most useless food to ever exist.

[@SK-qn5ry]

thank you so much . the kind of explanation u did it through animation is unimaginable . first i saw other utube solution didnot able to understand but finally through ur animation , life become easily

[@inkylace7045]

The first Ted-Ed riddle I have solved all by myself. Very nice video

[@rohankore3504]

Imagine this in real life where 16 out of 17 minutes gone to solve the riddle 😂😂😂

[@mosesblack8946]

Best comment!

[@samirdoncic6395]

Hahahahaha

[@samirdoncic6395]

Yet, you still have 1 min to save yourself, leave others behind hahahaha.

[@---cr8nw]

I real life, you take more chances than in theory. The bridge can only support two people's weight, you say? I'm finna find out.

[@RegulareoldNorseBoy]

EASY! JUST SKIP TO THE END OR READ THE COMMENTS ;-)

[@tahilaci2976]

You can find the perfect solution in like 2-3 minutes. After finding it, you realise you only have like 14-15 minutes left to actually implement it. :)

[@tahilaci2976]

+tahi laci Then 3 other people cheer as you found the perfect solution...

[@Jason608]

+tahi laci Yeah this actually took me 8 minutes to work out, so as the plan starts to execute, the zombies catch up to the professor and janitor and only the lab assistant lives. LOL!

[@firesong7825]

+tahi laci Well considering how fast the professor figured out how long it would take for the zombies to get there i think that he could figure out the best way to go across in 1 minute, which is all that is needed.

[@bitterherbs94]

+tahi laci if you have done the fox and chicken and grain puzzel then you can do this one in like 20s

[@snowangelnc4669]

+tahi laci Hopefully you figure it out on your way to the bridge. Otherwise, here's the alternative plan: 1. Figure out the plan and realize you've spent too much time thinking for it to now work. Come up with the alternative plan. (6 minutes) 2. Run across with the lab assistant. (8 minutes) 3. Return with the lantern. (9 minutes) 4. Cross with the janitor. (14 minutes) 5. Return with the lantern. (15 minutes) 6. Tell the professor you hope he now realizes how unwise it was of him to be messing with the undead. Then tell him you're shocked he didn't have some kind of escape planned out in advance. He could have even had an up to date plan posted at all exits and conducted regular zombie drills; but it's all too late now. (16 minutes) 7. Run across the bridge. Even if he tries to follow you in the dark you're safe because there's still only two people on the bridge. (17 minutes) 8. Cut the ropes.

[@naomisrandomness8223]

Cut the rope after all the zombies are on the bridge. Although I guess at that point they bridge would break anyway.

[@bettergaming2321]

Very good video, very informative, good work, very proud of you. (:

[@mnir4112]

There's no need to cut the ropes once you've made it to the other side because: 1. The zombies don't have a flashlight. 2. They don't know the bridge can only support two at a time.

[@NYCTO7]

+Manoj Niraula point 1, the zombies have nightvision as the prof stated point 2 exactly you're right! but their body mass must be lighter than live human though

[@borohhh]

+akhmad fadli Why exactly?

[@Kahadi]

+akhmad fadli Ok, so let's assume 2 zombies weigh less than 2 humans. There's many more than 2 zombies, though, and the difference in mass can't be enough for 3 zombies to weigh less than 2 humans, unless you've got zombies that are missing large portions of their bodies. Also, if there's only 2 or 3 zombies, 4 people (even if one is an old professor) could almost definitely handle them. Better question is why the professor didn't invent a way of controlling or killing the zombies. I mean one hand grenade tossed properly would easily wipe out the few zombies shown...

[@borohhh]

+tubefan90000 I meant why would zombies have a minor body mass.

[@Kahadi]

***** And? What does that have to do with me? I think his reasoning, though, is that they're rotting corpses, thus missing skin, maybe parts of limbs, etc, which wouldn't be more of a difference than the weight difference there'd likely be between the lab assistant and the janitor

[@surgedhaven8607]

Why do you need a lamp on a one way path?

[@ericsnider2342]

Drink Bleach Please... you don't

[@surgedhaven8607]

Destroyer Killer Exactly, so why did you need the lamp in the first place?

[@georgeofhamilton]

The bridge is dilapidated and has holes in it. They needed to watch their step.

[@BlazerT48]

Ace oh my god

[@juststoic3809]

Ace 😂😂😂😂

[@who.is.ash.2012]

I remember watching this as a 3 year old and getting nightmares until I was 8 about it 😭 edit: 55 likes?? Tysm!

[@anmeisplayhouse3785]

Same

[@hansgunnoo5159]

Ikr I found those zombies scary back then too

[@haiuyennguyen80]

​@@hansgunnoo5159Yes, I was traumatized

[@Lilttleratty]

I did this riddle in school 3 years ago and we all thought it was the hardest riddle ever and looking back at it it was really simple

[@jordanashe7656]

I can't help but think that you wouldn't need the lantern, like just go forward

[@AjitKumarreddragonclan]

exactly, its a bit odd

[@TheSleepyG_C]

you can fall off

[@mrthanos2404]

Maybe there are rotten planks on the bridge so you need to watch your way.

[@syedaromanarabegum6345]

@@TheSleepyG_C maybe if they slightly touched the rope after running like little bit then they could have the track of which way they are going.

[@miranda_turtle0566]

I was thinking that if you sent the professor and the janitor first with the lantern it would be ten minutes and then you and the other girl could run across without the lantern and it would be 12 in total

[@allupinyo]

copy+paste them to the other side and delete the old one

[@peter-mk4ig]

#BlackLivesMatter

[@aionchrono3045]

hahahaha, theres no ruoe about that so... a thumb up for ya

[@fiend_xdns]

Latias/ LatiRed you can just cut and paste so there IS no old one to delete smh

[@protek8]

just delete the zombies then thats it

[@jrami521jr]

I was thinking the fastest 2 cross first and once they cross the bridge shout to the other 2 to cross and worst case scenario the professor dies but he's old anyways and most likely since this saves on time he wouldn't die. Also the answer given is wrong because more than likely it would have taken the zombies 17 min from the moment he began calculating and even if he took that into account you're in a hurry so you probably didn't take into account the time it took to think of a plan so more than likely the answer given would be wrong

[@michellesantiagobautista]

I first saw this 7 years ago best thing ever. Since that day I watched every TedEd riddle video.

[@bartonseagrave9605]

I actually had a copy of the Zombies number one hit 'She's Not There' and they left me alone.

[@Scattertom]

If the old professor walks across with his hands on the ropes the whole way, can't he go without the lamp?

[@liz7]

+Alexander Freyr that's a good question.

[@ThatGuy-hc2ei]

+Alexander Freyr That's absolutely true, in reality no one need the lamp, the can all just hold the rope. problem solved, A+.

[@akero1388]

+Alexander Freyr I guess the lamp is important to avoid the broken planks

[@Scattertom]

Ale Ro Nothing is ever said about there being broken planks though. Merely that the bridge is old and can therefore only support two at a time. Furthermore, it is said that the lantern is just because it is too dark out to see without it, thus nothing is stopping anyone from simply approaching the bridge lit and then walking across blind. Nothing but the stated "There are no tricks, you can't swing across etc." or in other words _"Stop finding clever ways to solve my riddles,_ do it my way or leave"

[@Sheol02]

+Alexander Freyr Or there are simply no ropes.

[@tizzle27_20]

“You can’t befriend the zombies” WAEL GOSH DARN I THOUGHT WE COULDA BEEN BEST FRIENDS AND CROSS THE BRIDGE TOGETHER

[@felixlee9645]

Nope

[@aespugic]

tizzle27 _ hi tizzle again

[@tizzle27_20]

aespugic Why are you everywhere

[@PQAisha]

The bridge would collapse

[@qbertz]

PrincessQueen Aisha r/wooosh

[@phantomgt.]

man this takes me back

[@crazycowgaming817]

This is the first riddle I’ve solved with no help I’m so happy :)

[@pomegranatejuice3586]

If the guy had enough money to test zombies you’d think he’d have enough money to build a panic room

[@awesomeak9739]

And he also would have money to build a bridge which can hold more than 2 people at a time...Lol

[@player1marcio744]

Peg Kep Maine he have built the panic room,but the zombies could have blocked the entrance or the path

[@KCWelsh100]

where all your darkest fears are gonna come for you. come for you.

[@CheeseTheWhistle]

or the batcave

[@DhrithionVocals]

Lmao tru

[@SixerMerchant]

There’s people over there saying: how do you solve this? And then there’s me who’s over here saying: how do you give a headless zombie night vision?

[@Ananalias]

Best comment I read here

[@hoofly1323]

Maybe he doesn't have night vision and he's just following along with the other zombies by holding onto one of their shoulders

[@Kitz_Real]

Yeah how?

[@Aligorithm]

1 and 2 go first. Since they’re so quick, they each go side by side to graze the bridge railing on both sides while 1 holds the lantern in the center to check to see it’s intact all the way on either or both sides. Since 1 gets there first, 2 is able to see where the bridge ends by seeing the light. Total so far = 2 minutes 5, 10 |__________| 1, 2 1 leaves 2 on the safe side and 1 takes the lantern to go across back to 5 and 10 = 2+1 = 3 minutes 1 holds lantern to light the correct railing that 10 would hold onto seeing as he doesn’t need light. He’s slow because he uses the railing. 1 then gives the lamp to 10. 1 uses the rail grazing from the first time crossing to make it to the other side where 2 is. In the dark but can make noises as well to signify the end of the bridge to quickly help 1 know where it ends = 1 minute 2+ 1 + 1 = 4 minutes After 1 is back with 2, that means 10 is 1 minute in and has 9 left. 5 still waiting on the other side. Total so far = 4 minutes 5 |_____10_____| 1, 2 10 is holding onto rail and lantern. 5 watches the light slowly get smaller until he can estimate 10 is halfway (or counts 5 minutes) After 5 minutes, 10 stops with the lantern in the halfway point. Even though he doesn’t need it, this gives 5 a point to reach for and can graze the building rail. After 2.5 minutes, 5 and 10 are at the halfway point together. 4 + 2.5 + 5 = 12 so that 5 knows to start heading over and takes 2.5 minutes to catch up with him. 5 takes the lantern to finish the last 2.5 minutes of his as 10 uses the guard rail for the last 5 minutes of his. 10 uses the light at the end of the bridge as the guide as he is arrives on the 17th minute. Idk though 4 + 2.5 + 5 + 5 = 17 (the last half of 2.5 was simultaneous to the last half of 5) EDIT: okay I made it more complicated than necessary but I was thinking about it in a real life logic emergency scenario (without the zombies)

[@aerodynamicist4]

Now I know exactly what to do when I find myself in this situation

[@MrSkinnyWhale]

If I was in this situation I'd chuck the old fart off the bridge and bolt

[@me4109]

To run and leave the others to die...you will be safe...?

[@jjburns6509]

thank god

[@iLoveTurtlesHaha]

@@MrSkinnyWhale No, you should toss him at the zombies to slow them down. XD

[@hebajeba9677]

Just jump! weeee

[@gusrubio489]

Thanks so much, TedEd. I saw this video years ago, and since then, I've been in that exact situation 4 times! You really saved my life.

[@fidelherdez7971]

Haha nice

[@prathibhadhananjaya5880]

You've been with zombies 4 times?? 😨😨

[@tapan97]

Dude really, just go to the library

[@AwesomeBattleIsKindaCoolBruh]

How

[@TurnipBoy666]

IKR

[@paisleystarswhytho864]

I never solve the these riddles but I love watching them-

[@TortoiseShibaInu]

Ah, I remember when my teacher in grade school used to show these to us. Everyone wanted to sacrifice the professor, “HES LIVED A LONG, HAPPY LIFE!!” when the saw the zombies someone screamed, “THATS BLOODY!” I wanted the lab assistant to brew a potion and make us go back in time and NOT pull the lever. Haha. Then today I realized that the lab assistant doesn’t have anything with her at the time-

[@RRW359]

"Everyone must make it to the other side before you cut the bridge" That sounds more like a suggestion rather than a rule.

[@chrisyoung5929]

Yep I can do it in one minute, but the lab assistant looks kind of cute so maybe two, But then she will start getting all upset about the old man who is like her grandfather or something, gees chicks today. So I would have to play the hero and go back for the others. Now how great would I look if I let them go ahead while I waited here? Is that her coming back now? she loves me and we are saved! No, wait she has cut the ropes to the bridge!!

[@Sinking_Sunset]

@@chrisyoung5929 I laughed so hard at this lmao

[@elementgermanium]

The professor is literally making zombies maybe we should leave him

[@notoriusbookworm48]

@@elementgermanium yea I can live with that

[@razgrizknight8818]

You break the professor's legs and let him to be killed by his own, inhumane and ungodly creations. Send the assistant with the janitor across, wait till she returns and gtfo.

[@alilopez37]

😂😂😂

[@shiygirl16]

+Darth Praedatus YUP you dont have to out run the zombies you only have to out run the slowest person...=]

[@razgrizknight8818]

***** nah, the poor janitor didn't do anything wrong. The professor is the only one deserving to get munched

[@theboiledegg3310]

+Darth Praedatus yeah he created the problem.

[@hyperionbazooka122]

+Darth Praedatus Your profile pic haunts me

[@emcat52]

You wouldn't need to cut the bridge since you can see that all the zombies are crossing together and would have made the bridge fall anyway.

[@sniggdhajauhari]

He had to cut the bridge because weight of the zombies 'may not' collapse the bridge.

[@RO-mo2ul]

Of course the fastest guy is black

[@landon5967]

Rory O'Connor Of course you're the only person to pull the race card.....

[@RO-mo2ul]

HARAMBE I was joking

[@nicksacco5041]

was about to comment that

[@solitary2]

These dudes did their research. Hats off to them.

[@yourprobablynotgonnanotice4046]

Rory O'Connor I know!

[@somebodysomeone6834]

“Hey, what was your job as a college student?” “Oh, I was a pizza delivery guy!” “I almost started a zombie apocalypse.”

[@magicwand2764]

lol

[@agoose373]

*lol*

[@n_dubz3625]

-lol-

[@Menma_Furikake]

lol

[@justinbanh1597]

*lol*

[@ritasingh6872]

Hint for the riddle was given before the ans in animation by showing lab assistant to other side of the bridge

[@StillNight77]

Smart enough to solve a complicated riddle in a few seconds, but not smart enough to prevent this situation in the first place.

[@user-ri7nl9xb5b]

but why would I need to cut the rope when the bridge can only hold 2 people at a time anyway

[@ThaerRazeq]

Zombies are weightless, oh wait .. those were Vampires. :p

[@user-ri7nl9xb5b]

+Thaer Razeq but that doesn't explain that the bridge falls apart when another zombie steps on it while two other people are still on it

[@joyi.1883]

they may cross the bridge one by one

[@3kbschannel288]

+Joy I. But we don't have four lanterns

[@jrnone2047]

the bridge can hold many people, it is the lack of night vision that is the problem, one the zombies don't face with their night vision

[@nedflandersofficialyoutube1306]

Simple solution: Don’t built a lab on top of a mountain with a nearby gorge that can only be accessed via bridge.

[@milentanev7340]

Or take 10 million out of the 1 billion for the zombie development funding and invest in a helicopter.

[@werecanadian2]

just have a staff of two people on shift at a time..

[@Ozymandias83]

Don’t run projects that can be undone by 1 lever pull

[@jedi_cat_l4976]

But then if you didnt the zombies would get out too.

[@wenchen2508]

Yea, build it in a middle of a city and start a zombie apocalypse, not in the middle of nowhere. Lmao

[@fowleys]

Solved the riddle years ago... But keep coming back for the music. 🎶

[@user-ee8fc4wu5d]

Thanks for subtitles ❤😊

[@Stammer091]

what about the time it takes for them to plan this?

[@QGonline]

thats what I was thinking

[@youinanalternateuniverse6124]

Stammer091 Same here

[@mhannah3]

Stammer091 yeah that's what I thought

[@InsaneArenaSHOTS]

Stammer091 I am making it dramatic so. Let the guy be A, Girl be B, Janitor be C and Old Man be D. Now A and B go first, A returns promising B that he will save them all, time consumed is 3 mins. Now C and D goes nd time taken is 10 mins so total time consumed is 13 mins. Now B(girl) comes back running on her knees to save the love of her life, takes 2 mins. Total time consumed is now 13+2=15 mins. A french kisses B, crosses the bridge taking 2 mins. Voila, (15+2)=17 mins and they have crossed the way. Few days later the old man dies and then all the other 3 visit his funeral. Then A&B gets married, C raises a toast . A&B goes to the same old fucked up bridge spot for honeymoon, watching the zombies on the other side, sipping coffee. End of story. You can now do whatever you want.

[@pradyumnaiyer7456]

Anonymous lol 😁

[@crazyk2600]

So the professor couldn’t solve that one?

[@paroos77]

Professor is totally useless. He made zombies, run slowly, and now he couldn't solve problem too XD

[@nirrrro6125]

we're making sacrifices👀

[@mousumidebnath2170]

But he could loot royal mint of spain

[@medinavaughnchristans.2436]

@@mousumidebnath2170 HAHAHA MONEY HEIST

[@theterrorofdimensions1326]

The Professor is probably the one who came up with the solution. Because I seriously doubt the intern could think it up that fast. XD

[@Nryan-ks5tz]

i remember watching this ~6 years ago when i was only 12, the animation and the music scared me as a kid

[@shinykitsunelive]

The music in this one just gives it such an intimidating vibe

[@NagyerdeiKorisok]

As mentioned at 0:52, the professor is holding on to the ropes so --> he doesn't need lights. When he is on the other side he can shout.

[@Antphoneigh]

Hahaha, yes this is true! The narrator also says, 'you can barely see without the lantern'. 'You' refers to the fastest guy, so only 'you' need the light haha

[@resgeflegacy3936]

ha ha ha

[@jababokolishvili4171]

one of the best comments so far

[@TJKing-em1lz]

Thank you, thank you very much.

[@TJKing-em1lz]

***** That's exactly what I did with more words. :P

[@ariztrad4386]

I take the lantern and run across, leaving them for dead.

[@edgartj17]

Lmao omg your comment wins today xD im reading all these different ways of doing it and then i read your comment I just take the lantern and make a run for it and just died laughing lol

[@quakelovestoplay5193]

lmao I'd do the same

[@nPhlames]

That's my favorite video game.

[@nishitsaraf8144]

xD

[@cloudycat6693]

yeah but I' ll feel guilty

[@ZenHulk]

This is so old, it makes me feel old, first heard it in about 1979 in 4th grade.

[@wqftyzfs2y6]

couple years ago my science professor showed us this riddle. took me four fivr tries but i got it completely randomly

[@khalidh5933]

You said only 2 people could cross the bridge so if a horde of zombies take it then wont they all collapse making cutting the bridge completely irrelevent?

[@nerrick9602]

well what if the zombies smart enough so they cross the bridge 2 by 2 u know maybe the zombies are professor zombies because they came from lab, thats mean they are pretty smart

[@srithanyasatish868]

Fluffy Marimo how wud u know that all of them wud go at the same time?!? This is just an extra precaution that NO ONE GETS KILLED!!!! And ends up like the zombies

[@rjpena6273]

Nerrick 9 You do have a point! they maybe are intelligent!

[@khalidh5933]

Rj Pena its a theory and i can debunk it if the zombies were so smart they would not fall into the bridge when collapsed and that one zombie will not stand on the bridge because he knows that f he does he gonna fall of hmmmm?

[@shoubhikkoley8943]

the bridge can hold 2 PERSONS at a time, the weight of the zombies are not specified, and they specified though there are differences of weight among the persons too, any combination of persons can cross the bridge without breaking it, moreover that u just can not wait for the zombies to kill you. Sorry but your theory dosen't make any sense at all.

[@gabriels4433]

The answer is that I cross the bridge in one minute and every one else get left lol

[@williamkelly5689]

Muy bien

[@TimeToStahp]

very nice

[@lagreewithyourcomment]

@@AverageDunce r/foundthemobileuser

[@lagreewithyourcomment]

@@AverageDunce it doesn't matter on the council

[@me4109]

Same 😂😂😂

[@manhhoang6400]

The soundtrack genuinely impressed me

[@boRegah]

The newer riddle videos with the recap of the rules right before the answer segment are clearer and easier to tackle. You need the recap in text. Huge improvement.

[@GrubHuncher]

Paused the video, what I'm thinking is having the fastest guy carry the slowest guy on his back, with the slowest guy holding the lantern while being carried. Then the next two could get across with ease or the second fastest could carry the second to last fastest on their back.

[@GrubHuncher]

+Erik Y Damn.

[@GrubHuncher]

+Erik Y I never get these right.

[@rie4449]

+Erik Y That's what I thought, too. At least we tried.

[@GrubHuncher]

ㅎㅅㅎ 최 캐리 yeah lol

[@therandoms9675]

+Erik Y This is literally the perfect answer, I thought about this too.