need help plz help
(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.
(a)
20 IDENTICAL stickers to 5 DIFFERENT friends:
[26 + 5 - 1] nCr 5 ==142,506 ways - with no restrictions.
(b) Same as (a) above except everybody get " at least one sticker"
(26 - 1) nCr (5 - 1) ==25 nCr 4 ==12,650 ways
SOURCE: https://en.wikipedia.org/wiki/Twelvefold_way
{See the table at the very bottom of the page. Item #7 for (a), item #9 for (b)}
