- 06 Jun '04 18:11Say you have a number of fuses, wich ALL take exactly one hour to burn up completely when lit. Not all fuses burn at a constant rate, for example there could be a fuse that takes 5 minutes for the first half, then 55 minutes for the second half. What is the minimum amount of fuses you need to determine exactly 45 minutes have passed?

I do not know the answer (yet). - 06 Jun '04 18:59

Two, assuming you can light both ends of a fuse. Start by lighting both ends of one fuse and one end of the other. When the first fuse has burnt out, light the other end of the second fuse. By the time this has burnt out, 45 minutes have passed. I can't see a way to do it with a single fuse though.*Originally posted by TheMaster37***Say you have a number of fuses, wich ALL take exactly one hour to burn up completely when lit. Not all fuses burn at a constant rate, for example there could be a fuse that takes 5 minutes for the first half, then 55 minutes for the second half. What is the minimum amount of fuses you need to determine exactly 45 minutes have passed?**

I do not know the answer (yet).