A riddle I have enjoyed. Comments on self
Your goal is by burning the rope(s), to identify when exactly 45 minutes has passed. All you know about the ropes is:
* The ropes are of different length and you don\'t know how long they are.
* Each rope burns in precisely 1 hour.
* Each rope has a non-uniform density, meaning it is thicker at some points than others. Consequently, burning half a rope cannot be guaranteed to take 30 minutes.