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MathsJEE Main 24 Jan 2026, Shift 1·Q14·MCQ·Moderate

Binomial Theorem · Sum of binomial coefficients

Let S=125!+13! 23!+15! 21!+…S = \dfrac{1}{25!} + \dfrac{1}{3!\,23!} + \dfrac{1}{5!\,21!} + \ldots up to 13 terms. If 13S=2kn!13S = \dfrac{2^k}{n!}, k∈Nk \in \mathbb{N}, then n+kn + k is equal to
  1. (1)51
  2. (2)52
  3. (3)49
  4. (4)50

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