A basketball player scores with probability 1/4 on each independent shot. Find the probability of exactly 2 scores in 3 shots.
Answer and explanation
Correct answer: B. 9/64
- Step 1: Use the binomial formula P = C(n, k) p^k (1 - p)^(n - k).
- Step 2: P = C(3, 2) x (1/4)^2 x (3/4)^1 = 3 x 1/16 x 3/4 = 9/64.
Answer
9/64.
Why not the others: '1/16' ignores the failures and the number of arrangements; '3/16' forgets the factor (1 - p) for the misses; '3/64' forgets the binomial coefficient.
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