ChandlerBong
In how many ways can a mixed doubles badminton game be organized among 6 men – A, B, C, D, E, and F and 4 women – P, Q, R, and S such that A and P cannot play in the same game?
(Note: A game happens between 2 teams and in a mixed-doubles game a man and a woman pair up to play against another team of one man and one woman)
A. 30
B. 90
C. 120
D. 150
E. 180
Men: A, B, C, D, E, F
Women: P, Q, R, S
First, let's calculate the total number of games possible without any restrictions.
Choosing two men from six (6C2) gives us 15 combinations. These represent the two male players in two opposing teams. For instance, (A, _) vs (B, _).
Choosing two women from four (4C2) gives us 6 combinations. These represent the two female players who can be paired with the selected two men. However, there are two ways these women can be matched with the men, hence we multiply by 2. For instance, P and Q with A and B can be paired either as (A, P) vs (B, Q) or as (A, Q) vs (B, P).
Therefore, the total number of unrestricted games would be 15 (male pairs) * 6 (female pairs) * 2 (arrangements) = 180.
Now, let's consider the restriction that A and P cannot play in the same game.
If A and P are on the same team (A, P), the number of opposing pairs will be 5*3 = 15. This is because any of the remaining 5 men can be paired with any of the remaining 3 women. For instance, (A, P) vs (B, Q); (A, P) vs (B, R); (A, P) vs (B, S); etc.
If A and P are on opposing teams (A, _) vs (_, P), the number of opposing pairs will also be 3*5 = 15. This is because A can be paired with any of the remaining 3 women and P can be paired with any of the remaining 5 men. For instance, (A, Q) vs (B, P); (A, Q) vs (C, P), etc.
Therefore, the total number of restricted games equals the total number of unrestricted games minus the restricted games: 180 - (15 + 15) = 150.
Answer: D.