That's why bus prices
are never (well, rarely- especially the higher cost tickets) simply 2-coin transactions. Say it's £1.80- you stick £2 in the box and forget about the other £0.20. To do it correctly, the minimum number of coins you'd need is a £1, 50p, 20p and 10p.
Which means that when you inevitably miss out one coin you're forced to give them more than the ticket price.

It's almost thievery, but not quite.
( uberdeity Wondered why Owen Lars knew of the term "hell" on, Fri 28 May 2010, 22:09, Reply)