MATH 12 HELP!!
posted by tina .
a pizza store offers 15 different toppings on its pizzas.
what is the probability that 4 randomly selected toppings will include salami and green pepper?

There are 15 choose 4 ways to choose 4 toppings. There are 15 choose 2 ways to choose salami, green pepper, and 2 other toppings.
P{salami and green pepper) = C(15, 2) / C(15,4). 
A pizza parlor has a choice of toppings for its pizzas. From these toppings, how many different topping pizzas can be ordered? Assume that the order in which the toppings are listed does not matter.