P1. Peter celebrated his birthday on one day, and two days later his older twin brother, Paul, celebrated his birthday. How could this be?
P2. Walking home one day, you take a short cut along the train tracks. The tracks cross a narrow bridge over a deep gorge. At the point you are 3/8 of the way across the bridge, you hear the train whistle somewhere behind you. You charge across the bridge, and jump off the track as the train is about to run you down. As it happens, if you had gone the other way, you would have reached safety just before being run over as well. If you can run ten miles per hour, how fast is the train moving?
P3. You and a friend decide to have an egg spinning contest. What can be done to make sure that your egg spins the longest?
P4. You live in a three story building. In the cellar there are three light switches, in the attic there are three responsive lights. You have to find out which switch belongs to which light. There are a few restrictions though: You can’t see anything at the outside from the cellar where the switches are. But you do know that from the beginning all the switches are in the “off” mode. If you only go up once to check the lights in the attic how can you tell which light switch belongs to which light?
More to come…
