Amusements in Mathematics

Henry Ernest Dudeney (10 April 1857–24 April 1930) was an English author and mathematician who specialised in logic puzzles and mathematical games. In 1917 he published Amusements in Mathematics, 430 puzzles with solutions. Amusing indeed!

An example:

Two trains start at the same time, one from London to Liverpool, the other from Liverpool to London. If they arrive at their destinations one hour and four hours respectively after passing one another, how much faster is one train running than the other?

Solution: One train was running just twice as fast as the other (hint: when the trains pass eachother they are running for the same time).