Mario's Pizza has 2 choices of crust: deep dish and thin - and crispy. The restaurant also has a choice of 5 toppings : tomatoes, sausage, pepeers, onions, and pepperoni. Finally, Mario's offers every pizza in extra cheese as well as regular. If Linda's volleyball team decides to order a pizza with 4 toppings, how many different choices do the teammates have at Mario's Pizza?

Answer

20