Question

You order a pizza at a restaurant. You can choose 2 toppings from a list of 12. How many combinations of toppings are possible?

Answer 1

Explanation:

By binomial theorem,

the formula = n!/[ (r!) (n-r)! # ! is a factorial. e.g. 5! = 5 × 4 × 3 × × 2 × 1

Sub n = 12, r = 2

12!/(2! x (12-2)!) = 66