Question

"How many ways can Rudy choose 4 pizza toppings from a menu of 13 toppings if each topping can only be chosen once?"

Answer 1

Answer:

715 ways.

Step-by-step explanation:

We are asked to find the number of ways Rudy can choose 4 pizza toppings from a menu of 13 toppings if each topping can only be chosen once.

We will use combinations formula to solve our given problem.

The number of combination n chosen r at a time is given by formula:

$C(n,r)=\frac{n!}{r!(n-r)!}$

$C(13,4)=\frac{13!}{4!(13-4)!}$

$C(13,4)=\frac{13!}{4!*9!}$

$C(13,4)=\frac{13*12*11*10*9!}{4*3*2*1*9!}$

$C(13,4)=\frac{13*11*10}{2}$

$C(13,4)=13*11*5$

$C(13,4)=715$

Therefore, Rudy can choose 4 pizza toppings from a menu of 13 toppings if each topping can only be chosen once is 715 ways.