You have two ropes. Each rope takes one hour to burn. The ropes are not homogeneous, in other words if you cut the rope in half the two halves will not burn for a half hour each. Create a way to burn a rope for exactly 15 minutes. You can light the ropes as many times as you want and stop the fire as much as you want. But the ropes can only be light from the ends.
Hint: Cutting the ropes will only hurt you seeing as how you will know nothing.
2006-12-07 16:18:40 · 9 answers · asked by jazzman1127 2 in Entertainment & Music ➔ Jokes & Riddles
I don't think I was clear, you have to create a timer, meaning you don't have one. The only way you will know how much time elapsed will have something to do with the ropes. There is no clock/timer/or time keeping device. Sorry for the confusion.
2006-12-07 16:24:33 · update #1
Again, looking at the answers I feel I wasn't clear. The rope is not homogeneous, a quarter section taken from one end will not burn at the same rate as another section from the very same rope. Meaning if you cut it in equal halves and light each half on fire the two halves will extinguish at different times.
The answer is to fold the first rope in half and light both sides of the folded rope, (thus making a rope that burns for an hour, become extinguished twice as fast, i.e. 30 minutes) and then when you light the folded rope you also light the just one end of the second rope. Once the folded rope extinguishes you dose the fire of the unfolded rope. Leaving you with a section of rope that will burn for a half hour. Then you light both ends of the new half-hour rope, allowing for the half hour rope to extinguish twice as fast as normally; therefore, 15 minutes.
2006-12-07 18:37:33 · update #2
just burn the rope for 15 minutes and then when time is up, put it out.
2006-12-07 16:22:15 · answer #1 · answered by Brent S 2 · 0⤊ 1⤋
Take the two halves of a rope and cut it .The rope will burn for 15 minutes.
2006-12-08 09:27:03 · answer #2 · answered by bellefire016 4 · 0⤊ 0⤋
I don't know, only guessing.. fold the rope in two, tie
something on it at that point, then fold it again, and tie something on it.. you would have four sections of 15 minutes.
Why two ropes?
2006-12-08 00:29:40 · answer #3 · answered by scrubbag 7 · 0⤊ 0⤋
light the rope let it burn for 15 minutes and blow out the fire, no one said the rope had to burn out, just has to burn
2006-12-08 00:22:46 · answer #4 · answered by Anonymous · 0⤊ 0⤋
fold one in half, mark the ends on the ground, light both ends (next to each other) and when half of your rope is gone, the 15 min are over
2006-12-08 00:29:55 · answer #5 · answered by carla 3 · 0⤊ 0⤋
light, let her burn 15 minutes, put out fire!
2006-12-08 00:30:14 · answer #6 · answered by Shelia 3 · 0⤊ 0⤋
measure the rope into quarters and stop it when its reached the quarter mark
2006-12-08 00:55:47 · answer #7 · answered by ~♥~ *CHEEKY* ~♥~ 6 · 0⤊ 0⤋
Light it and stop the fire after 15mins?
2006-12-08 00:22:56 · answer #8 · answered by sand 3 · 0⤊ 0⤋
damn you've already answered it oh well 2 points any way
2006-12-08 04:40:48 · answer #9 · answered by Anonymous · 0⤊ 0⤋