Answer :
[tex]a) \: 4 \times 3 \times 2 \times 1 = 24 \: ways[/tex]
[tex]b) \: this \: one \: is \: a \: little \: more \: \\ complex \: so \: bear \: with \: me \\ poss \: 1 = all \: \: tie \: for \: first \\ poss \: 2 = 3 \: tie \: for \: second \\ poss \: 3 = 2 \: tie \: for \: third \\ poss \: 4 = no \: one \: ties[/tex]
They can all tie for first place in one way,
which is, that they all arrive first with no order.
Possibility 1 = 1 way
If one person arrives in first place, this leaves 3 to tie for second, All 4 players can arrive first and the other 3 would have to tie in second so,
Possibility 2 = 4 ways
If two people take the first two spots, this leaves two people to tie for third place, All four players can occupy the first position and the other 3 can switch in second leaving two to tie at last. and this can happen in 4 ways.