Salad Toppings: Donald Wheeler is ordering a salad at a Ruby Tuesday restaurant. He can purchase a salad consisting of just lettuce, or he can add any of the following items: cucumber, onion, tomato, carrot, green pepper, olive, mushroom. How many different variations of a salad are possible? Solution There are 7 different topping choices (ignore lettuce, since he has to get that), so we need the number of subsets of a set with 7 elements: 2^n=2^7= 128 choices.