A basketball player scores with probability 1/3 on each independent shot. Find the probability of exactly 2 scores in 3 shots.
Answer and explanation
Correct answer: C. 2/9
- Step 1: Use the binomial formula P = C(n, k) p^k (1 - p)^(n - k).
- Step 2: P = C(3, 2) x (1/3)^2 x (2/3)^1 = 3 x 1/9 x 2/3 = 2/9.
Answer
2/9.
Why not the others: '1/9' ignores the failures and the number of arrangements; '1/3' forgets the factor (1 - p) for the misses; '2/27' forgets the binomial coefficient.
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