theCodeToGMAT wrote:A university cafeteria offers 4 flavors of pizza - pepperoni, chicken, Hawaiian and vegetarian. If a customer has an option to add extra cheese, mushrooms, or both to any kind of pizza, how many different pizza varieties are available?
a) 12
b) 16
c) 8
d) 20
c) 10
Take the task of building a pizza and break it into stages.
Stage 1: Choose one of the flavors
There are 4 flavors of pizza (pepperoni, chicken, Hawaiian and vegetarian), so we can complete stage 1 in
4 ways
Stage 2: Choose whether to add extra cheese
We can either add extra cheese or not add extra cheese, so we can complete stage 2 in
2 ways.
Stage 3: Choose whether to add mushrooms
We can either add mushrooms or not mushrooms, so we can complete stage 3 in
2 ways.
By the Fundamental Counting Principle (FCP) we can complete all 3 stages (and thus build a pizza) in
(4)(2)(2) ways ([spoiler]= 16 ways[/spoiler])
Cheers,
Brent
Aside: For more information about the FCP, watch our free video:
https://www.gmatprepnow.com/module/gmat-counting?id=775
