Two Ropes
A friend at church keeps feeding me these marvelous puzzles. Here is a good one, nice and simple:
You have two ropes, and each takes one hour to burn all the way from one end to the other. But they burn at an uneven rate—fast, then slow, then fast, then slow, etc. Thus if you cut a rope in half, the two halfs would not necessarily each burn in half an hour. So using these two ropes, how would you measure 45 minutes?
I’ll post the solution in a few days.
28 May 2007 at 10:44 am
The solution!:
Light both ends of one rope and one end of the other rope. The first rope will burn completely in half an hour; the second will have burned halfway. At that point, light the other end of the second rope. It will finish burning in another fifteen minutes.