I hate myself for failing to see the solution to this ... :evil:
Suppose that you have two fuses, each of which takes an hour to burn from one end to the other, and as many matches as you need.
Describe how you can use the fuses to time a period of 45 minutes.
Trivial? There's a catch, though: The fuses burn at irregular rates, so you can't, for example, just cut a quarter off one of the fuses. All you can assume is that each fuse has a "burn time" of one hour.
If nobody has posted an answer in a few minutes, I'll edit this message and add the answer in a "spoiler" section. No Googling allowed!!!
Stesilaus
ANSWER
Light one fuse on both ends. When it finishes you should have (30 minutes)
Take the other fuse and cut it in half and light both ends of each half. When that fuse is all burned up 15 minutes should have passed. (15 minutes)
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