If n C r denotes the number of combinations of n things taken r at a time, then the…
Mathematics · JEE Advanced · NTA Exams — Permutations and Combinations
If nCr denotes the number of combinations of n things taken r at a time, then the expression
nCr + 1 + nCr – 1 + 2 × nCr equals
nCr + 1 + nCr – 1 + 2 × nCr equals
- n + 2Cr + 1
- n + 1Cr
- n + 1Cr + 1
- n + 2Cr
Answer
(A) n + 2 C r + 1
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