Data management, counting methods

2. A school badminton team has 15 players. 9 of the players are in the Junior division and 6 of the players are in the Senior division. The team needs to select 4 members to go to a tournament. [10 marks] a) How many ways are there to select 4 players to go to the tournament? b) How many ways are there to select 4 players to go to the tournament if Jeff or Colleen cannot both go. (they don't get along). c) How many ways are there to select 4 players to go to the tournament if 2 must be Junior and 2 must be Senior? d) Suppose the 4 players are selected at random to go the tournament. what is the probability that at least one Senior player is chosen? e) Suppose the 4 players are selected at random to go the tournament. What is the probability that exactly 3 of the players ar Junior