If ⁿ⁺¹C_(r+1): ⁿC_r: ⁿ⁻¹C_(r-1) = 55: 35: 21, then 2n + 5r is equ… | JEE Main 2024 Mathematics PYQ | Jeeify

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MCQMediumJEE Main 2024 · 6 April, Shift 2Combinations (C(n,r))

If $^{n+1}C_{r+1} : ^nC_r : ^{n-1}C_{r-1} = 55 : 35 : 21$ , then $2n + 5r$ is equal to:

A
$60$
B
$62$
C
$50$
D
$55$

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