In how many different ways can you make up a total of
one pound  from any or all of the following coins?           

1p, 2p, 5p, 10p, 20p, and  50p.

Example: 1x50p + 3x10p + 6x2p + 8x1p = £1.

You can change this to dollars and cents or Euros and cents etc if it feels better!  I don't think there's a 20-cent coin in American currency, but then there's no 25p coin in Sterling. This shouldn't stop you tackling the problem.