How many times does the long hand of the clock pass the short hand between midnight one day and midnight the following day? As both hands are together at the starting time of midnight this does not count as a pass.
A store has on sale a computer and word processor small enough to fit in your pocket. It can add, multiply, subtract, divide, and write in all languages. A delete device will correct any error. No electricity is required to operate it. The price? Only a few cents! How can the store make a profit by selling it so cheap?