Time and Work Problems - Shortcuts and Tricks

[@TheOrganicChemistryTutor]

Final Exams and Video Playlists: www.video-tutor.net/

[@joshuaamado559]

In community college I used this guys videos for calculus, at university i used him for organic chem and physics, now that im trying to be a pilot im using his videos to study for the aviation entrance exams. When I make it im gonna owe my career to this dude ive never met or seen lol.

[@rrts1942]

Pls come back here to tell the result.

[@joshuaamado559]

@@rrts1942 I scored in the 70th percentile (top 30%) on my exam. So I did great! This guy is the real deal

[@juancampo2196]

Congratulations!

[@brianjohnson7513]

safe to say you owe this man your first check

[@douglasvarcasia4910]

I'm using him as well to study for ASTB and he breaks down everything so well

[@ibeeadane4430]

I graduate with a degree because of you. I joined the aviation industry because of you. Now am reading to become a pilot. Whoever you are, may God bless everything you have!!

[@ghgfrghfrhgdxvgredghhgvfth1573]

Hi mate congratulations, can I ask what career you currently do within the aviation industry? Thank you

[@wakuwaku3190]

wow congrats!

[@johnvincentderoma]

Congrats Bro!!!🎊🎊🎊😎😎😁😁😁

[@iLLsauce]

Same I’m trying to join the navy as a pilot 😬 gotta get the test score first

[@ariwilkes4115]

I'm also trying to become a pilot but, it's really hard I heard but still I'm gonna try.

[@WinsteinDc]

From Nigeria here, you're a genius sir.. Got an exam next week, and this just solved my problems.. Bless Sir

[@buffsamson]

Update us about your exam bro. Btw goodluck

[@WinsteinDc]

@@buffsamson Sure I will, it's tomorrow...Thank you

[@buffsamson]

Goodluck brother you can do it

[@buffsamson]

@@WinsteinDc how did it went brother?

[@WinsteinDc]

@@buffsamson Just about texting you now.. It went fine.. God bless, really appreciate

[@cbesthelper404]

This instructor is one of the best along with Tyler Dewitt! They are excellent at presenting all kinds of math and chemistry problems. I teach the subjects myself, and I frequently recommend their videos to students.

[@sarinonayam263]

This guy is very helpful. I really hate maths but because of him math is become easier. I got higher grades in math because of this guy thanks a lot. You're more effective then my math teacher. Keep it up 🙏

[@devondevon4366]

For the second problem. Mark and Kelly can finish the job in 4 hours working together, but Mark could do it in 6 hours if he worked alone. So in one hour he completes 1/6 of the job: Also in 1 hour both of them could complete 1/4 of the job. We don't yet know what fraction of the job Kelly could complete in 1 hours so set it to be y , therefore Kelly could complete 1/y of the job in 1 hours.. set up the equation . 1/6 (Mark) + 1/y (Kelly)= 1/4 (the fraction of the job both could complete working together so solving for y gives 2 y + 12 =3 y , y=12.. Kelly alone could finish the job in 12 hours

[@LarkAnderson-lq1gi]

kelly is a slacker fr

[@evanspaulmuwonge1511]

JG, I graduated at KYU in Uganda with an A in calculus exam because of you. Thanks so so so so much. Your work was so awesome in support of my excellent performance. It was the only A in the exam during my year.

[@jessyhughes9948]

Hahah I just graduated and these are the kind of math questions that are actually necessary in the real world. High school taught me nothing of importance

[@deathcallsu5162]

YOU SOUND LIKE A 2 YEAR OLD !!! JK

[@sagatad.8245]

this is middle school math though? You must've went to a bad high school

[@elibertbasubas7905]

@@sagatad.8245 yes buy algebra in middle school?

[@ayasuniverse]

I was struggling with this concept to prep for the SAT but just watching two examples of your video made me understand the whole thing, U LEGEND

[@madhaviduvuru9497]

Lol

[@twsdogexl2298]

6:45 correction the LCM is 12 but this it still works eitherway

[@danielamaning5765]

I am from Ghana currently in the us and I studying for the ASVAB in next year God willing and I must admit you tutoring is awesome Thank you

[@devondevon4366]

19:02 Lisa , Karen and Tom took 2 hours (working together). Lisa 3 times faster than Tom, and Karen twice (2) as fast as Tom .How long will it take Karen to complete the task on her own? Let 6x (hours) be the time its takes Tom to complete the task ALONE, therefore it will take Lisa 2x (hours) to do so ALONE, AND Karen 3x (hours) to do so ALONE. Therefore, it would take all three to complete the task in an HOUR by the following equation 1/6x (tom) + 1/2x(lisa) + 1/3x (karen) = 1/2 1 + 3 + 2 =3 x or 6=3x or x =2.. recall tom is 6x , so 6x2= 12hrs, lisa 2x, so 2x2= 4hrs and karen 3x so 3 x 2= 6 hrs. Answer : it will take KAREN 6 hours to complete the task on her own.

[@abejueladanieljaymarkc.4062]

hey i just wanna ask how did you get tom's hours did you multiply the 3×2? from lisa and karen? also how did you get lisa and karen's time? did you divide 6x to 3 for lisa and 2 for karen?? HOPE U'LL ANSWER THISSS TIA!!!!!

[@devondevon4366]

​@@abejueladanieljaymarkc.4062 You can use x for Tom or 6x (or any other unknown, 9x, 100x, etc.), but make sure that Lisa is 1/3 of Tom's unknown and Karen is 1/2 of Tom's unknown. I used 6x for Tom since, for me, it was easier to get 3x and 2x for Lisa and Karen, respectively. Let us use 'x' instead for Tom; then the fraction of the work he would do in one hour is 1/x and the fraction Lisa would do = 3(1/x) or 3/x and the fraction Karen would do = 2(1/x) or 2/x since Lisa and Karen worked 3 and 2 times as fast as him, respectively. All three completed their fraction of the work per hour by this equation 1/x + 3/x + 2/x= 1/2 = 6/x= 1/2 6 x 2= 1. x (cross multiply) = 12= x, so Tom would complete 1/12th of the work in 1 hour, so he would complete the ENTIRE work in 12 hours. Still, since Lisa worked three times as fast as Tom, she would complete it in 4 hours (12 divided by 3) by herself, and since Karen worked twice as fast as Tom, she would complete it alone in 6 hours (12 divided by 2). If I had used '6x' instead for Tom, then (if done correctly, x would =2) and I would have to multiply 6 by 2 to get 12 for Tom and divide 12 by 3 to get Lisa's 4 hours ( since she worked three times as fast as Tom) and also divide 12 by 2 to get Karen's 3 hours(since she worked twice as fast as Tom) If I had used '3x' for Tom, then I would have to use 'x' for Lisa and '1.5'x for Karen ( and if done correctly, x =4, which would be Lisa) and would have to multiply 4 x 3 to get Tom (12) and would have to multiply 4 by 1.5 to get Karen's (6) or divide 12 by 2 to get Karen's (6). So it doesn't matter if I used 'x' or '6x', etc., for Tom, provided I used 1/3 of Tom's unknown for Lisa and 1/2 of Tom's unknown for Karen.

[@abejueladanieljaymarkc.4062]

@@devondevon4366 OMG!! Thankyou so muchhhhh i understand better now thankyouuu :>>>>>

[@nzarthal]

This guy is gonna get me through school. Better and more efficient than any teacher I've had.

[@hmedina79]

Best tutor on youtube, hands down. That's why he has so many subscribers. Does anyone know what he uses for his presentations. I'm an online tutor (I'm good and I'm cheap for one-on-one sessions through Calculus), I have to get whatever he uses!

[@extempetus7414]

I'm dumbfounded when I realized that the shortcut formula is just the one you use in parallel circuits resistance and it does make sense now! Of course you will use a parallel solving equation to solve a parallel related problem...

[@black_shade3610]

When I search about math problems I really scroll down until I find your channel because I know I'll understand it when its this channel :) new subscriber here :)

[@saki7952]

War ninkaan legend waaye walhi

[@saki7952]

Julio Gonzales what a great teacher you are! I have never seen my entire world a teacher like you.

[@mastererick9312]

this guy deserves a billion sub

[@devondevon4366]

Sally painting 1/3 of that room per hour while John is painting 1/6 of that room per hour. Together they paint half of the room per hour 1/3 +1/6 or 2/6 + 1/6= 3/6 or 1/2 in one hour . Then in two hours they would finish that room when working together. So answer is two hours

[@paulaalvano2049]

I tried to figure this for DAYS so I could explain it to my Son for school. I finally understood it thanks to you!!!

[@surajvarne3992]

Thanks dude you LITERAALY help me in both the SAT, IB, and the basic Respectt

[@mathsmack7515]

bro watch the complete tutorial on time and work kzbin.info/www/bejne/apnCq52IfLCIqrc

[@amienawadil2416]

Si jg u r so helpul..u know i hve leant a lot from your you tube channel...that time i dont even know even adding fraction..now it is easy for me..now i learn work problem..thx a lot sir jg...i watched almost all ur vedeos..God bless you sir JG..from philippines..

[@georgesadler7830]

Mr. Organic Chemistry Tutor, thank you for an excellent analysis on Time and Work Problems- Shortcuts and Tricks in Algebra One/Two. I found word problems challenging, however from watching and do these types of problems increases my understanding of the subject.

[@jovanmagtoto1682]

thank you for this sir, my mind became open to difficult problems after I watched your videos. Thank you also for encouraging us to do first the solving before we continue to watch, it helps me to think and analyze also. Thank you

[@devondevon4366]

8:25 Alice can complete 1/6 of the task , Kristen 1/9 and Ronald 1/18 in an hour or 3/18, 2/18 and 1/18 respectively. Therefore if they worked together they could complete 6/18 of the task (3+2+1 over 18) in 1 HOUR,, 12/18 of the task is left (or twice as much of what they would/could complete in one hour). So working together they could complete the task in 3 hours. Answer 3hours

[@teofilosalinas660]

Simpliest solution ive searched.This guy is the answer

[@lightbeing1113]

whew chile...the lisa, karen and tom word problem gave me headache problems lol...Love your videos. It really helped me pass my entrance exam. Thank you alot.

[@neverever7821]

Last question blew my mind. You're the best

[@underthemooon]

You are THE BEST at explaining things, I only look for your videos now when I need math help. Thank you!

[@Top_Corners3]

very helpful - covering all types of possible questions.

[@templetetradactyl5862]

I agree with the others about how helpful these videos are and am just as grateful. Thank you so much.

[@umarraja878]

Thank you very much! I am in year six and I will be doing the 11plus this video really helped!!

[@authentictexan7487]

This guy honestly teaches better than most teachers

[@goldenboycomedy8666]

💯

[@workubelay340]

I don’t know what to say about your math videos, really appreciate it!! I passed my math exam because of you.

[@rizeandrealize]

I have watched many different KZbin to understand this topic. Your are the best! Thank you so much!

[@bbmm9541]

Everything about this channel is perfect. Thank you to this teacher and your team.

[@kimayapanash8998]

i love this channel so so so much. my friends beg me to teach them the things i learn from him

[@saki7952]

Should inform them about the chennel. Don't be selfish

[@amienawadil2416]

True...so they cn learn too..

[@sally6366]

that's right john. i paint faster than you

[@batboyhood3]

HAHAHAHAHA *HAHAA* HAHAHA _HAAHAHAHAHAHA_

[@marnilanap4932]

I used to just watch and see another video when done. But this time, i 👍 clicked this button and typed a comment.

[@mouserat2108]

The best tutor in youtube.

[@__playsguitar5796]

Thank you for this hope you make more content.

[@alexanderaningat3616]

This video is so helpful specially for the future math educators.💕 You're so genius

[@inferious777]

Another way to solve these kind of problems (or the logic behind it) is to assume that to complete a task you require 100 work units, you can then use the amount of time taken from each worker how much work units they can complete in 1 hour, you add them up to find out the amount of work units done by everyone working simultaneously in 1 hour and divide 100 work units by it.

[@RoohaAli]

Kindly write example for better elaboration. Write 8:04 for this question

[@abdisalanelmi-oh3oz]

This man is very helpful for differnt subjects

[@astermaze5088]

I'm preparing for my upcoming entrance exam and your videos are really helpful sir. Thanks a lot💕

[@jlee804]

best math channel on youtube

[@AB-hc1wo]

KZbin is the best teacher

[@Sheikxlove123]

this was simply, I feel dumb for not knowing this, thank you!

[@TheOrganicChemistryTutor]

You're welcome

[@lolimsooedgy7809]

@@TheOrganicChemistryTutor we need more math problems plsss

[@evan.5967]

anime Lover 😎

[@hey9530]

Just commenting so u get more views. Keep up the great work!

[@ranyabaga-an2483]

I love your videos.. you teach better than my math teacher.

[@ILYFried_Rice]

YOU'RE SUCH A LIFESAVER TYSM!! ❤❤❤❤❤❤

[@tochukwuideba693]

Published 5yrs ago but still saving lives in 2024

[@Sunflowersandthesun]

Brooooo this is so helpful!!!!!! Thank you very much!!!!!!!!!! 💙💙💙

[@mathsmack7515]

bro watch the complete tutorial on time and work kzbin.info/www/bejne/apnCq52IfLCIqrc

[@kimbananas]

Hi! I just want to thank you. Your videos helped me a lot and I passed the examination. Thank you very much. 😊

[@KOFIKNOWS]

He’s gonna be the real reason I pass tf put this civil service test

[@fatumamohammedseid3769]

TNX so much man Ur guiness & LOVE Ur Voice 😊❤

[@bandini22221]

Excellent dissertation, sir. I was with you right up to the last problem.

[@samhitap7873]

nice voice and ur a smart teacher

[@mercyrosero904]

I'm not good at Math and Science but still i take CE course. How brave I am.😂

[@jonathananniban6440]

Yeah me too I'm a ce student

[@mr.purrfect6500]

not surprising, also a ce student here

[@alanrapoport2090]

From Al I like to do the 3 person problem in my own way as I did Mind your Decision’s A+B =2 hours, A+C =3 hours and B+C=4 hours. The 3 do the job in 2 hours but Tom does 1/6 th of job or an entire job in 12 hours A little thought shows that in 12 hours Karen does 2 jobs or a job in 6 hours and Lisa does 3 jobs or a job in 4 hours. So that makes a total of 6 jobs in 12 hours or a job in 2 hours as we are given.

[@ibrahimakande5651]

You're amazing!!! I exactly enjoy math all because of your videos.

[@TencupsGaming]

Please go over these kind of videos. Tricks and shortcuts videos are so helpful like lmfao

[@jalalgk2415]

What a brilliant teacher!!!!!!!

[@JohnArthurGregoryDolor]

Hello! I noticed a pattern whenever we're dealing with 3 people. Basically the formula (follow the same flow from the og formula) is 1/x = 1/2x + 1/3x +1/6x It's just my own theory so feel free to use it at your own risk.

[@patricklewis2745]

Man, I wish I had you as my math teacher.

[@alvanotieno6490]

u are a math saviour thnx so much

[@johnbrennan3372]

The ratio of their contributions is 3:2:1 .So Lisa does half the work; Karen 1/3 and Tom 1/6 in a two hour period. Since Karen does 1/3 of the work in 2hours, on her own it would take 3 by 2 hours= 6 hours. Lisa would 4 hours and Tom 12 hours.

[@elleltakebede5201]

I'm really grateful for this video's. If it weren't for them I would have failed my maths test for shore.

[@Keemham]

UR A LIFEEAVER MAN HOW CAN I THANK YOU😍

[@segevmalool9072]

John actually hates working with Sally, so he heckles her by hiding the paint. Therefore, Sally is working slower because she must search for the paint and it takes 9 hours. Another way to think about this is in terms of redundant constraints: V1*6 + V2*3 = 2 rooms painted V1*6 = 1 room painted V2*3 = 1 room painted Once you find the velocities, you can transform the problem to the time domain to ask for solutions to (1/6)T1 +(1/3)T2 = 1 And add the constraint T1 = T2 To find T = 1/(1/6 + 1/3)

[@wenxiazhang6943]

Does these math problems (hours) formula apply for school? Does it work? For school. For instance, middle, high, and etc. Plz answer. Your videos are extremely useful! Like for example, if we are doing a math problem about hours, does this formula that you showed us work? I really want to know!

[@mohammedal-shaboti7939]

the last question can be solved by sum both side of the three equations: 2/A+2/R+2/N = 1/7.2+1/12+1/9 => 1/A+1/R+1/N = 1/2(1/7.2+1/12+1/9) = 1/6

[@IsabelRodriguez-nv2ue]

Fantastic explanation!!!. Thank you very much for your videos. They are awesome!!!!

[@okolifaithfulness1851]

Love the way u derive this formulas

[@coastalhalfling7094]

Hi! Can I request a video involving work problems about man-hours? Thanks! Love your contents!

[@ramanathansabesh8862]

people before aug 17, 2018: (insert internal dying and screaming)

[@templeuche]

You are just too good... How do u do these?....awesome

[@mathsmack7515]

bro watch the complete tutorial on time and work kzbin.info/www/bejne/apnCq52IfLCIqrc

[@redroad9949]

One doesn't need a "formula" for every simple concept. Understand the concept and you won't have to learn all these formulas. The only "concept" you need here is the definition of rate of work = total work/total time. You can then shuffle this around to express things like: total time = total work/rate of work and so on. For problem 1, "paint the room" is the work. Let's call that w. So John's rate = w/6, and Sally's is w/3. Combined rate is w/6 + w/3 = w/2. Time when working together = w/(w/2) = 2. That's it. If you simply memorize a formula without understanding the (simple) concepts behind it, you'll be able to solve a problem that fits "the format" exactly and struggle if something is changed. Don't do that.

[@jaliilshugriaden]

You are my hero sir ❤❤❤❤❤❤

[@junoroldan6310]

Thank you very much! It's very helpful.

[@genicadelara5243]

You're a great teacher. THANK YOU.

[@PandoVlogger]

Thank you sir! it was very useful for me

[@kinrobbermasatosuhwa]

You make this so easy, thanks a lot ❤

[@christianfrizzell6919]

No ads, no shoutouts, just helping with math 🙏

[@theresaroque1525]

I do not now why but I'm starting to feel something with his voice and intelligence after watching more than 10 videos. Like I like to hear it over and over again. Shemss HAHAHAHAHA🙈

[@syedsaadqainhaider2456]

i was so happy that i was able to do the last problem

[@cameloogabooga]

THANK YOU SMMMM❤❤ I HAVE A TEST TM WISH ME LUCK

[@wiggles7976]

I'd like to derive the formula given at the beginning, namely 1/T_AB = 1/T_A + 1/T_B. There are two workers combining their efforts to achieve a task. You have one worker, worker A who does 1 job per T_A, where T_A is the number of hours it takes him to do the job. Similarly, worker B does one job per T_B. (In the example, T_A = 6h and T_B = 3h). Let T_AB be the amount of time it takes both to complete one job when working together. For worker A, N=1[job]/T_A is the rate he produces completed jobs, where I'm using [job] as a unit. We think of N as worker A's "jobs per hour". Similarly, M=1[job]/T_B is worker B's "jobs per hour". Clearly, if they work together for T_AB, by definition they will have completed one job, thus (N)(T_AB)+(M)(T_AB)=1[job]. We thus have (after dividing by [job] to cancel the unit) (1/T_A)(T_AB)+(1/T_B)(T_AB) = 1 => 1/T_A + 1/T_B = 1/T_AB. Similar reasoning can extend this to 3 simultaneous workers, 4 simultaneous workers, and so on.

[@shawnd.8498]

Correct. Problem #5 requires a bit more thought to work through. Aya will take 4X longer to work on the bike.

[@Cassie-cs1eg]

Let's face it, you just simplified the whole shebang that gave me a headache for 2 days and explained it in less than 25 min?! Should've come to you sooner😅

[@kingdaniel4756]

07:27 Can someone give me an explanation why should we subtract that? Where does the 4x on subtraction came from??? I don't understand... I love Math and I am practicing it. I want to understand Math concepts since this is one of my most favorite hobbies.

[@MoeenaliTunio-ib1gp]

Completely understandable reaching.

[@eftiomasefa7973]

Your contents are the best but I have some comments and it is better if you use the background white color and if the fonts of your texts are bigger I think it's going to be perfect

[@luffyonepiece5704]

Thank you sir ❤

[@DokterrDanger]

32:00 Dude, why so complicated! High-School students like me will convert 1/7.2 into 10/72, then make that 2(1/Tabc) into 2/Tabc (i.e x) and THEN find the LCM.

[@colpireduro9255]

Try solving it and let's see what's the answer

[@dtecum]

John and Sally problem: 6/3=2, 2/2=1, 2+1=3, 6/3=2 hours.

[@jclarkmathclass9529]

All you have to do is multiply the two numbers for the numerator and add them for the denominator (working against you subtract).

[@kevingarrett8403]

This is so great. I'm helping a college student and I sure wish this channel existed when I was in highschool

[@mathsmack7515]

bro watch the complete tutorial on time and work kzbin.info/www/bejne/apnCq52IfLCIqrc

[@ThinzarLinnLett]

just want to know that how this formula comes from..btw, thanks very much! This really helps me a lot