Should Alice marry Bob?
Two problems: 1. You are in an airport and are walking from the main departure lounge to a rather distant gate. On the way there are several moving walkways. There is a small stone in your shoe, which is annoying enough that you decide that you must remove it. If you want to get to the gate as quickly as possible, and if there is no danger of your annoying other passengers, is it better to remove the stone while on a moving walkway or while on stationary ground, or does it make no difference? 2. You want to give £1,000 to somebody as a 21st birthday present. The person in question is just about to turn 16. A savings scheme offers a guaranteed interest rate of 3 per cent for the next five years, provided you save the same amount at the beginning of each year.
