JEE MATHEMATICS MCQ: COMBINATIONS

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In a club election the number of contestants is one more than the number of maximum candidates for which a voter can vote. If the total number of ways in which a voter can vote be 126, then the number of contestants is

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Correct option: D

Option D (7) is correct because the equation

{\;^n}{C_1} + \ldots + {\;^n}{C_{n - 1}} = 126

simplifies to

2^n - 2 = 126

, which gives

n = 7

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