In how many ways can a committee of 2 be chosen from 9 people?
Answer and explanation
Correct answer: B. 36
- Step 1: Order does not matter, so use combinations: C(9, 2) = 9! / (2! x 7!).
- Step 2: C(9, 2) = 36.
Answer
36.
Why not the others: '72' counts ordered selections (permutations) instead of combinations; '18' multiplies n and k; '45' adds n to the correct count.
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