Question

A pizza restaurant offers nine choices of vegetarian toppings for pizza. In how many ways can you choose four toppings?

Answer 1

We check the following points

1. The order does not matters

2. No repetition

3. we cannot choose all the available choices. we need to select only 4

If order does not matters then we use combination

Formula is nCr = $\frac{n!}{r!(n-r)!}$

We choose 4 from 9

So 9C4 = $\frac{9!}{4!(9-4)!}$

= $\frac{9!}{4!(5)!}$ = 126 ways