Question

A student is allowed to select at most ‘n’ books from a collection of (2n+1) books. If the total number of ways in which he can select at least one book is 63 then n =

• A. 3
• B. 4
• C. 5
• D. 6

Answer 1

The correct option is A 3

By verification
$\left(i\right)n=3;2n+1=7\Rightarrow {}^7{C}_1+{}^7{C}_2+{}^7{C}_3=63$
So Ans = (i)