A university cafeteria offers 4 flavors of pizza - pepperoni, chicken, Hawaiian and vegetarian. If a customer has an option (but not the obligation) to add extra cheese, mushrooms or both to any kind of pizza, how many different pizza varieties are available ?
Choices:
A) 4  B) 8  C) 12  D) 16  E) 32
There are 4 flavors of pizza and each can be:   1. Without cheese and mushrooms;   2. With cheese;   3. With mushrooms;   4. With cheese and mushrooms.   So, the total number of pizza varieties is  4*4= 
<gadget id="calculator"> 4*4</gadget>
<output>16</output>
16.   Answer: 16.
<result>D</result>
A university cafeteria offers 4 flavors of pizza - pepperoni, chicken, Hawaiian and vegetarian. If a customer has an option (but not the obligation) to add extra cheese, mushrooms or both to any kind of pizza, how many different pizza varieties are available ?