SOLUTION: A football team consists of 20 freshmen and 20 sophomores, 15 juniors, and 10 seniors. Four players are selected at random to serve as captains. Find the probability that a. all 4

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Question 912151: A football team consists of 20 freshmen and 20 sophomores, 15 juniors, and 10 seniors. Four players are selected at random to serve as captains. Find the probability that
a. all 4 are seniors
b. there is 1 each: freshman, sophomore, junior, senior
c. there are 2 sophomores and 2 freshmen
d. at least 1 of the students is a senior
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
total 65: 20F, 20S,15J,10Sr
4 Selected
P(all Ss) = %2810C4%29%2F%2865C4%29
P(1 each) = %28%2820C1%29%2820C1%29%2815C1%29%2810C1%29%29%2F%2865C4%29
P(2S AND 2F) = %28%2820C2%29%2820C2%29%29%2F%2865C4%29
P(at least Sr) = 1 - P(no Sr) = 1 - 55C4%2F%2865C4%29