With decimalisation in 1971, British money became much more sane/boring. This puzzle uses the old system of coins: 1/2 d., 1d., 3d., 6d., 1/-, 2/-, 2/6, and 5/-. (The values are, respectively, 1/2, 1, 3, 6, 12, 24, 30, and 60 pence. There might have been a few other varieties – it did change over time – but we will ignore them.) How many ways can you make change that adds up to 1 pound (240 pence) if you can use no more than two of any one denomination?
Submit your answer to Gene Wirchenko <firstname.lastname@example.org>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, June 7, 2017 at noon Pacific Time. I will post the answer shortly after.