An expensive pint

A gorilla went into a quiet country pub, put a ten pound note on the bar and asked for a pint of beer. The barman served him and thinking 'he's probably not very bright' gave the gorilla £5 change. Then, wishing to appear friendly, the barman said "We don't get many gorillas in here".

" I'm not surprised" answered the gorilla, " if you charge them all £5 for a pint of beer"