0, 1, 3 cannot be made
Find amounts of money that can be made up in two ways so that one set of coins has twice as many coins as the other (but not using only 1c and 2c coins). e.g. 71c is 50c, 20c, 1c (3 coins) or 20c, 20c, 20c, 5c, 5c, 1c (6 coins)