The coefficient of x²y³z² in the expansion of (x + y + z)⁷ is
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Correct answer: B. C(7, 2) × C(5, 3)
Explanation
The multinomial coefficient is 7!/(2!3!2!) = 210. Choose positions for x² (C(7,2) = 21), then for y³ among the remaining 5 (C(5,3) = 10): 21 × 10 = 210.More Discrete Structures and Optimization questions
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