(a) Find the number of ways that Magnus can give out 20 identical stickers to 5 of his friends. (Not everyone has to get a sticker.)
(b) Find the number of ways that Magnus can give out 20 identical stickers to 5 of his friends, if every friend gets at least one sticker.
Partitions of 20, into at most 5 parts:
192 ways.
20 + 0 + 0 + 0 + 0
19 + 1 + 0 + 0 + 0
18 + 2 + 0 + 0 + 0
18 + 1 + 1 + 0 + 0
17 + 3 + 0 + 0 + 0
........and so on
