You have two ropes. You know that each rope takes one hour to burn from one end to the other, but that the burning does not take place at a constant rate (i.e. half the rope may burn in one minute, and the other half will take 59 more minutes to burn).

How would you go about measuring a 45 minute time interval with just these two ropes?

light one rope at both ends
light the other at one end

after 30 minutes, the first rope will burn out, and the second will have 30 minutes to go.

now, light the unlit end of the second rope. it will burn for another 15 minutes giving you 45 minutes of burn :) Easy

Posted by ubergeek on 2002-12-26 00:23:16