Beautiful Money

A gang of counterfeiters get a new extremely expensive printing machine, and at great expense, buy some plates, which they were assured were 99.9% perfect. They buy a large consignment of paper which also was virtually identical to the real paper. Gleefully, they switch on the machine and print a few off. They were delighted with the quality of the paper, the inks, and the printing itself - it would fool the best investigators in the whole world - if it wasn't for the fact that the notes were all £18 notes! What were they to do? Eventually, someone suggested going over to Ireland, and changing some of their £18 notes - those stupid Irish wouldn't realise they were being conned! A few days later, and they're in a small Irish pub in the back of beyond, and they ask if they could change one of their beautiful £18 notes. "Sure, no problem," says the barman. "Would you like 3 £6 notes or 2 £9?"