Question

how do i start to solve this
Harry has a choice of a veggie burge and a regular pizza
he can have three toppings his choices are
lettuce pickles onions tomatos and sprouts that is five items
how many combinations can he have
I think i multiply 5 x 3 and get 15 can you tell me is this right

First topping:

5 choices
sEcond choices 4 toppings
third choice 3 toppings

Answer: 5*4*3

nCr= N!/(n-r)!