IMO: D
Question Stem:B=10
S=6
F=8
No. of players playing all 3 sports = 0
No. of players playing 2 sports \(\geq\)1
Selection:1 player from B&S
1 player from S&F
1 player from F&B
Then remaining 3 players are selected one after the other from the set of players who play either 1 or 2 sports
St 1: The number of seniors on both the basketball team and the soccer team is the same as the number of seniors on both the football team and soccer team, and three less than the number of seniors on both the basketball and football team.Consider the following fig:
Attachment:
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If x is count of players who play both F&B
Then No. of players who play S&F = B&S = x+3
Now given S = 6
6 = 2x+s
B=10
10=2x+b
F=8
8 = 2x+3
Thus
If x=1 then
1c1 1c1 4c1 9c1 7c1 5c1 = 1*1*4*9*7*5 = 1260 ==>multiple of 4
If x =2 then
2c1 2c1 5c1 9c1 7c1 5c1 = 2*2*5*9*7*5 = 6300 ==> multiple of 4
St 2: There are 5 seniors that play one pair of sports, 2 that play another pair, and 2 that play the last pair.It doesn't matter which pair of sport is played 5 or 2 or 2. We end up with same selection
2c1 2c1 5c1 9c1 7c1 5c1 = 2*2*5*9*7*5 = 6300==>multiple of 4
Hence Suff