Question

Use the formula for nCr to evaluate the given expression.

27C2 = ___ (Type an integer or a simplified fraction.)

Answer 1

351

Explanation:

27C2 = 27! / 2! × (27-2)!

= 27×26×25! / 2×1 × 25!

= 27×26 /2

= 27×13

= 351