Can you solve this? Star if you like!?!
Question:
Can you solve this? Star if you like!?
You are given two ropes and a lighter. These items are the only things you can use. Both ropes have the following qualities: if you light one end of the rope, it will take exactly 1 hour to burn to the other end.
However, both ropes do not have to burn at a uniform rate. In other words, a rope does not burn at a rate of 30 minutes at the first half and 30 minutes at the other. For instance, half the rope may burn in the first 5 minutes and the other half would take 55 minutes.
In addition, the second rope will also take an hour to burn from one end to the other and would also burn at some varying rate. Also, this varying rate is not necessarily the same as the rate for the first rope. Given this information, you are asked to measure a rate of 45 minutes. Can you do it?
Answers:
Light both ends of one rope (A) and one end of the other (B). After 30 minutes, rope A will be completely burned up and there will be 30 minutes of rope B left. Light the other end of rope B; it will burn up in 15 minutes. Total time elapsed since starting the ropes on fire: 45 minutes.