Question 602204
The key word "up to" means everything below that value and that value is included. So "up to 3 toppings" means you can choose 0, 1, 2, or 3 toppings.



There are C(7,3) = 35 ways to choose 3 toppings


There are C(7,2) = 21 ways to choose 2 toppings


There are C(7,1) = 7 ways to choose 1 topping


and finally, there is only one way to choose no toppings 



So overall, there are 35+21+7+1 = <font color="red">64</font> different ways to choose up to 3 toppings.



Note: C(n,r) = (n!)/(r!(n-r)!). So for example, C(7,3) = (7!)/(3!(7-3)!) = 35