You are a cook in a remote area with no clocks or other way of keeping time other than a four-minute and a seven-minute hourglass. On the stove is a pot of boiling water. Jill asks you to cook a nine-minute egg in exactly 9 minutes, and you know she is a perfectionist and can tell if you under cook or overcook the egg by even a few seconds. How can you cook the egg for exactly 9 minutes?
1. Flip both hourglasses over and drop the egg into the water. 2. When the 4-minute timer runs out, flip it over (4 minutes elapsed, 3 remaining on the 7-minute timer). 3. When the 7-minute timer runs out, flip it over. (7 minutes elapsed, 1 remaining in the 4-minute timer) 4. When the 4-minute timer runs out, flip the 7-minute timer over. (8 minutes elapsed. 6 minutes remained in the 7-minute timer, but flipping it over leaves one minute’s worth of sand on top. When it runs out exactly nine minutes will have elapsed.)
Alan fires a bullet from his hand gun and his friend Wade catches the bullet with his bare hands. The gun shoots actual, deadly bullets. The bullet does not touch anything but air after it leaves the gun and until it reaches Wade’s hand. Wade is uninjured. How does he do it?
Alan fires his bullet from a .25 ACP (Automatic Colt Pistol), which will reach a maximum height of 2,287 feet. He shoots directly upward while standing at the base of Burj Khalifa, a 2,722 foot tall building.
Wade is a window cleaner at that building, waiting at 2,287 feet. When the bullet reaches that height and is about to go back down again, he reaches out with his bare hands and catches it.
Two legs sat upon three legs with one leg in his lap. In comes four legs, grabs one leg, and runs off with him. Up jumps two legs, grabs up three legs, throws it after four legs, and makes him bring back one leg.