4 Interview Puzzles That Will Test Your Brain Power

[@LOGICALLYYOURS]

Hey everyone! I'm finally back on KZbin after such a long break. I truly apologize for the delay and appreciate your patience. I’ll share the reason for my absence soon, but I promise to stay consistent with posting new videos. Thank you for sticking around!

[@zohaib1537]

Glad you came back.

[@ਨਿਰਮਲਸਿੰਘ-ਗਿੱਲ]

Welcome back

[@vmadhavan435]

All good

[@HerveSACUTO]

It’s so good to see you back I like so much your videos !! 🎉

[@fizixx]

Nice to see you back! 😎

[@ajishjohn2872]

Out of the box thinking for 1st question : Although the shortest distance must be the one mentioned, a logical answer would be the one wherein he has to carry the water for the least amount of time, reducing the total effort. Coz his speed would reduce once he has the water

[@LOGICALLYYOURS]

Brilliant thinking! An important constraint indeed while implementing practical solutions.

[@DeepeshMaan]

​@@LOGICALLYYOURS When the farmer’s speed decreases after picking up water, the path should adjust to minimize total effort, similar to light bending to minimize travel time (Snell's Law). In this case, the farmer’s path would follow an analogy to n1 * sin(i) = n2 * sin(r), where n1 and n2 represent the speeds before and after picking up water."

[@yaduvarma9854]

Absolutely right...

[@bharathram7245]

​@@DeepeshMaan Exactly! It is in the textbook

[@thatreilyrandomguy]

Final question: Answer is 4x17 and 2x16. First I realised that 40 was useless because it can be made up from 16 and 24 so if it's a solution theres also a solution without it so no point including 40. 39 also seemed suspicious. I tried just using 16s at first but came up with 96. I thought about replacing 1 with a 24 but that was too much. Then I realised I could swap 4 16s with 17 to gain 4 on the total.

[@sandippal8908]

💯

[@LOGICALLYYOURS]

You’re absolutely right on the spot. 😁

[@3dworld519]

​@@LOGICALLYYOURSIs there any systematic way to approach this like using algebra?

[@FildasFilipi]

Lets write an equation 16a + 17b + 23c + 24d + 39e + 40f = 100. Note that the number of shots is at most 6, since 7x16 would be too much. As such 0

[@Patrik6920]

@@FildasFilipi a note: 16a + 17b + 24d + 40f = 100 [17b=68]

[@DeepeshMaan]

The first problem is analogous to the law of reflection of light, represented as n1 * sin(i) = n2 * sin(r), where n1 and n2 are proportional to the speed of the entity (in this case, the farmer) in the respective mediums. Since both mediums are identical (n1 = n2), the equation simplifies to i = r, which corresponds to moving in a straight line if the boundary between the two mediums is crossed.

[@yaduvarma9854]

For the last question - I divided 100 with the shortest number which was 16 - I got 6 with 4 as remainder... So I replaced 4 of those 16s with 17 and that was the answer..

[@LOGICALLYYOURS]

Yes that’s perfect explanation

[@3dworld519]

​@@LOGICALLYYOURSIs there any systematic way to approach this like using algebra?

[@hikari1690]

@@3dworld519 idk about algebra, but from a computer science point of view you can setup an equation: 16i + 17j ... + 40n Then since you know that you won't be able to use more than 7 shots (because the smallest point is 16 and 7x16>100) you can use loops to find out what combinations of i,j,k,l,m and n can give you 100. Worst case scenario you will be checking 8⁶ combinations (6 nested loops checking 0-7) which is admittedly alot, but will probly just take a few minutes and you'd get all possible combinations

[@zohaib1537]

Final question answer is 2 times 16 + 4 times 17 = 100.

[@3dworld519]

Is there any systematic way to approach this like using algebra?

[@ayyaanfaras9241]

beed waiting for soo long for new riddles! Thank you for being back 😁

[@sushantkanojiya1856]

Good to see you back. 🎉

[@agytjax]

The solution to the last puzzle is Subset sum problem

[@vmadhavan435]

Bro finally came back!

[@hikari1690]

Hmmm, for the final puzzle, does the competition have a limit on number of shots? For now I just calculated: 100/16 = 6 remainder 4 which means replacing 4 of 16 with 17 you can get 2x 16 and 4x 17. But I'm unsure if this is the only solution nor am I sure if this solution is the most efficient. What if the rules say less than 5 shots? I mean I can do 16i + 17j + 23k + 24l + 39m + 40n and try all combinations such that i + j + k + l + m + n ≤ 6 but I hope there's a neat trick in the next video or I'll be sad!

[@LOGICALLYYOURS]

A good question indeed, there’s so limit on number of shots… however, we should also prove that there is no other combination. I hope I’ll post a detailed solution in the next video.

[@hikari1690]

@@LOGICALLYYOURS yay! Looking forward to it

[@analoghardwaretops3976]

Your reasoning of 6 shots is right..😅

[@hikari1690]

@@analoghardwaretops3976 I mean, the maximum shots you can take is 7 cause it's 100/16 rounded up. For problems like these you always estimate the maximum number of attempts you have by dividing the goal with the smallest value available. This way you can estimate the time needed to bruteforce the solution as well as keep track of your own solution. And it just so happens you can get a solution with 6 moves here. As a computer scientist I'd need this value to know I'd need to make a 7 deep tree and use BFS or DFS to find the solution(s).

[@soifakhter841]

Appreciate your efforts💖 Welcome back🎉

[@LOGICALLYYOURS]

Thank you for the warm welcome. 😊

[@3dworld519]

Is there any systematic way to approach this like using algebra? Even though I found the answer for the last question by random guessing of 2×16 + 4×17

[@LOGICALLYYOURS]

I came up with a systematic approach which I’d post in the next video.

[@superhightemperature2941]

16+16+17+17+17+17=100

[@akashramkamal7539]

I think there are two solutions for the 2nd question. One is aligning the point A in the path of the straight line and another is aligning B in the path of the straight line in between X and Y Edit: There is also a third solution where you align the midpoint of AB on the straight line in between X and Y

[@LOGICALLYYOURS]

Hey Akash, good to see your comment. Well, if you try from the opposite side (starting from village Y), then also you’ll get the same path as shown in the video, please give it a try. However, your mid point approach won’t give the shortest path, reason being that the villagers need to travel on the land, whereas reaching the midpoint of AB involves travelling on land+water (which is not possible).

[@analoghardwaretops3976]

Walking distance from home to river & river to cowshed , both must be equal..for the shortest distance.. (2 sides of the isosceles triangle)...

[@Smallpriest]

I don't understand why the last question is tricky

[@LOGICALLYYOURS]

I also felt the same, but after asking several candidates I realized that it’s certainly a tricky one!

[@spuneet156]

17*4, 16*2 100

[@3dworld519]

Is there any systematic way to approach this like using algebra?

[@ucBenNguyen-wg5ci]

Welcome back🎉

[@saicharanthamidalapati5258]

4*17+2*16

[@BooksForever]

Six arrows will put her at 100 exactly; but I fail to see anything tricky about it.

[@BooksForever]

I tried to give people the answer without actually spoiling it for them.

[@ManjeetRani-v5n]

arreee!!! ye banda zinda hai!!

[@VenkatSai04]

For 1st question, he would build a cowshed near river

[@thanados.....6562]

Two =16 Two=39 Total =110

[@mohsinabdullah1008]

2times(16)+4times(17)

[@ankurdubey8432]

16 16 17 17 17 17

[@vaibhavsharma7630]

Last question answer could be 2 x 40 and one arrow between 17 and 23 . That would give us a total of 100 with minimum number of arrows. 16x4 and 17x2 participant will lose because she would have won in the first 3 rounds only.

[@d.SAiNi.]

No, your final score will be 103 (40+40+23), as higher score to be given If the arrow breaks a line between two scoring zones.

[@HerveSACUTO]

My solution very easy and fun : I cut 6 wooden rod at the size 40mm 39mm etc etc So 6 wooden rod , and make a mark on paper length of 100mm , and try to align my 6 rods for make 100mm on paper Very fun to do and no tricky mentally mathematic calculs 🧮, à children can solve this Game is higher form of research ….

[@comps_52_mankritsingh84]

Nice thought,but you need to use one rod more than once ie you may need to use 16 twice,thrice or even more. So you need to have multiple rods of the same length to do this activity successfully

[@LOGICALLYYOURS]

Thanks @HerveSACUTO for the detailed explanation. I really appreciate your approach.