Answer: Hello mate!
we have 11 toppings, and you can choose 5 of them.
Then the total possible combinations of pizza with 5 toppings is equal to the combinatory number between 11 and 5 (this is because is the same situation where you use first topping A and after topping B, and where you use first topping B and after topping A, for example)
where the combinatory number between A and B is:
[tex]C(A,B) = \frac{A!}{(A-B)!B!}[/tex]
where ,in our case, A is 11 and B is 5.
then we have:
[tex]C(11,5) = \frac{11!}{6!*5!} = \frac{11*10*9*8*7}{5*4*3*2} = 11*3*2*7 = 462[/tex]
Then the right answer is A = 462, there are 462 pizzas with 5 different toppings from 11 possible ones.
