A TV sports commentator claims that 45 percent of all football injuries are knee injuries, assuming that this claim is true what is the probability that in a game with 5 reported injuries:

a) all are knee injuries?

b) none are knee injuries?

c) at least 3 are knee injuries?

d) no more than 2 are knee injuries?

I am looking for some direction, confused as to where to begin, looking for any kind of help, it'd be much appreciated.