Problem of the Week
for Friday, November 14

Mr. Kandel ( a notorious pyromaniac ) has decided to get rid of his stopwatch and to time his science experiments by setting things on fire. He has ordered a box of two-minute ropes, which, if one end is lit, are guaranteed to last exactly two minutes. Unfortunately the ropes are very cheaply made and burn irregularly, speeding up and slowing down, so we cannot guarantee that they burn halfway in one minute, for instance. Henry has two ropes left. Can you figure out a way for him to time exactly three minutes? How about a minute and a half?

Winn's Solution: Animated Solution: