SOLUTION: Hi beloved tutors, I need help on this question, would you please help me? Thanks The pupils in Kang Aroo School have invented a game - wallball. A wallball team has three playe

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Question 1024304: Hi beloved tutors, I need help on this question, would you please help me? Thanks
The pupils in Kang Aroo School have invented a game - wallball. A wallball team has three players. The coach of the team has seven players at his disposal. But two of those players are twin brothers who have brought only one pair of shoes and cannot both play at the same time. How many teams of three players can the coach field?
(A) 20 (B) 30 (C) 40 (D) 120 (E) 210
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
The coach could leave the twins out and make some teams with the remaining 7-2=5 players.
5%2A4%2A3%2F%281%2A2%2A3%29=60%2F6=10 Teams could be made that way.
The coach could also include one twin or the other twin along with a pair of the other players.
The coach would have 5%2A4%2F1%2A2=20%2F2=10 possible pairs of non-twins,
and with two choices for the twin two include,
that would make 2%2A10=20 different team that include a twin.
So the coach could make 10%2B20=highlight%2830%29 different teams.