Two fuses problem
This logic puzzle about measuring time by burning fuses takes 30 seconds to explain, but can frustrate you for days. As with most of my favorite puzzles, this one will become extremely obvious once you know the solution. And no, it’s not a cheesy solution. Interestingly enough it isn’t hard initially because it has a lot of options, but because you have to think about the problem in the right way.
You are given two fuses and a lighter. Each fuse will burn for exactly 60 minutes. However the rate of burning is irregular, so cutting a fuse in half does not mean a burn time of 30 minutes. You need to time 45 minutes. How do you do it?