The value of _ r=1 ^ 15 r^2 ( ^ 15 C_r ^ 15 C_ r-1 ) is equal to:

JEE Main 2016 Mathematics question

The value of is equal to:

Answer: (4)

Simplify the ratio of binomial coefficients first. Using ,

= = .

Substituting, each term becomes $· =

Create a free account to read the complete working (5 steps), and practise questions like this in a timed test.

Question ID VK-115558