Logical Interview Question

**teapot418** · 7 March 2017, 19:26

Originally posted by europetractor View Post

They gave me the following question which I solved my way and not the "right" way they suggest on here https://www.brainbashers.com/showpuz...sp?puzzle=ZVGA

==
You have two ropes.

Each takes exactly 60 minutes to burn.

They are made of different material so even though they take the same amount of time to burn, they burn at separate rates.

In addition, each rope burns inconsistently.

How do you measure out exactly 45 minutes?
===

My solution was to use the first rope to map its hour-burning interval to a repeating event which event I would repeat over and over for the duration of the burning. For example over 1 hour I may get 200 repetitions of the event and then figure out how many repetitions equal to 45 mins and this way solve the puzzle.

I still stand by my answer because the officially suggested one (see the link ) seems wrong because of the fact the rope doesn't burn at equal speed...

It does.

**PurpleGorilla** · 7 March 2017, 19:28

Logical Interview Question

Fold it in half and then half the half to get the 75:25 point then start the burn from there?

**GB9** · 7 March 2017, 19:37

Use a watch, clock or timer?

Why would you want to work for a company that tells the time by burning ropes?

**europetractor** · 7 March 2017, 19:58

Originally posted by GB9 View Post

Use a watch, clock or timer?

Why would you want to work for a company that tells the time by burning ropes?

It doesn't scare me that they expect candidates to write code interview answers on paper.. it scares me that she said they actually had candidates who could write code on paper.

**LondonManc** · 7 March 2017, 20:18

Originally posted by europetractor View Post

It doesn't scare me that they expect candidates to write code interview answers on paper.. it scares me that she said they actually had candidates who could write code on paper.

As part of a broad-reaching MI role, I've had to write out SQL statements on paper; if you're in at a higher rate than others you've got to prove you're worth it. It helped considerably that two candidates failed by asking for crayons and felt tips instead.

**europetractor** · 7 March 2017, 20:44

Originally posted by LondonManc View Post

As part of a broad-reaching MI role, I've had to write out SQL statements on paper; if you're in at a higher rate than others you've got to prove you're worth it. It helped considerably that two candidates failed by asking for crayons and felt tips instead.

Well I think the purpose of computers is to help us rather than make few people like them and render the rest too humane.

**vwdan** · 7 March 2017, 20:52

I figured you could light the first rope at both ends. Should average out at 30 minutes. Then, cut the other rope in half and then light at both ends which should give you the additional 15 minutes.

Though, to me as a sometimes overly literal person, I absolutely hate this questions. The very fact it says "burns inconsistently", implies you can't use any outside tools and then says "Measure exactly" makes it a bulltulip question.

Take his calibrated spirit level and make that shelf perfectly flat with no other tools. Stupid.

**europetractor** · 7 March 2017, 21:01

Originally posted by vwdan View Post

I figured you could light the first rope at both ends. Should average out at 30 minutes. Then, cut the other rope in half and then light at both ends which should give you the additional 15 minutes.

Though, to me as a sometimes overly literal person, I absolutely hate this questions. The very fact it says "burns inconsistently", implies you can't use any outside tools and then says "Measure exactly" makes it a bulltulip question.

Take his calibrated spirit level and make that shelf perfectly flat with no other tools. Stupid.

oh i get it now

**AtW** · 7 March 2017, 21:14

MF would have punched the interviewer for exactly 45 minutes

Logical Interview Question