A pizza place offers 6 different cheeses and 12 different toppings. In how many ways can a pizza be made with 1 cheese and 3 toppings?

You need to "choose" three toppings, which means you need to do a combination (versus a permutation, which would only be needed if you cared about the order that the toppings are added to the pizza, which you obviously don't care about). The combination formula is n! / (r! (n-r) !).

12! / (12-3) ! (3!) = 220 ways to choose toppings.

**know that! Means 12*11*10*9 ... * 3*2*1

Then multiply that by the 6 cheeses to get 220*6 = 1,320 ways. (Each choice of three different toppings can be paired with six different choices for cheese)