A school has \(n\) pupils, of whom \(r\) play hocket, where \(n\geqslant r\geqslant2.\)
All \(n\) pupils are arranged in a row at random.
What is the probability that there is a hockey player at each end
of the row?
What is the probability that all the hockey players are standing together?
By considering the gaps between the non-hockey-players, find the probability
that no two hockey players are standing together, distinguishing between
cases when the probability is zero and when it is non-zero.