A pizza shop offers nine toppings. No topping is used more than once. What is the probability that the toppings are pepperoni, onions, olives, and mushrooms?

Answer 1

There are 2^9 number of subsets or 512
This includes the nullset, which corresponds to a pizza with no items.
{pepperoni, onions, olives, and mushrooms} is one of those subsets.
So the Prob(pepperoni, onions, olives, and mushrooms) = 1/512