Math Riddle: You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer, and a five-minute timer, how can you boil the egg for only two minutes?
Answer: When the water is bubbling, turn the three-minute clock and five-minute clock over. At the point when the three-minute clock runs out, put the egg in the bubbling water.
At the point when the five-minute clock runs out, two minutes have passed and it is time to remove the egg from the water. You needn’t bother with the four-minute clock for this enigma.