Qualcomm Interview Question: A brain teaser question where... | Glassdoor

Interview Question

Embedded Software Engineer Interview Boulder, CO

A brain teaser question where we have to find out

  45 minutes with the help of two ropes. Given that one rope burns completely in 1 Hr and the rate or burning is not consistent.
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Interview Answer

4 Answers

0

I assume that both ropes have the same non consistency.
If you burn from one end it takes 1H.
If you burn it from both ends it takes 1/2 H.
To get 1/4 H, burn it from both ends and the point that in the first rope the fires got together.

Anonymous on Mar 11, 2013
0

I assume that both ropes have the same non consistency.
If you burn from one end it takes 1H.
If you burn the first rope from both ends it takes 1/2 H.
Immediately after the first rope burnt, burn the second rope from one end and the middle point that fires reached each other in the first rope.
To get 1/4 H, burn it from both ends and the point that in the first rope the fires got together.

Anonymous on Mar 11, 2013
6

Burn first rope from both ends, and second rope from one end only.

When First has completely burned, 30 mins will have passed and second rope will have 30 mins left on it.

Now burn second rope, which has burned for 30 mins already, from both ends, this will burn a 30 minute rope at twice speed, making it complete in 15 mins.

This will be 45 minutes total.

Anonymous on May 23, 2015
0

I've faced same question in ASSIA interview

Anon on Jun 4, 2015

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