Mario's Pizza has two choices of crust: deep dish and thin-and-crispy.

Thanks, that makes sense.

I'm glad the explanation helped. Keep at it!

5x2x2 =20, this is a mgmat questions. The end is slightly different.

need great help to correct my steps/understanding:
I need to choose one of crust with 4 toppings.
so I need to choose 1 from 2 and 4 toppings from 5:
my work is as follows:
2/1! multiply 5x4x3x2 / 4!
= 2 / 1 x 5x4x3x2/4x3x2x1
= 2 x 5
= 10 choices
why my answer is wrong, need great help
is cheese and regular is also part of the equation.
Many thanks

Many thanks Bunuel really really appreciate it

Is this actually sub600? cos it's seems some users are as confused as I am. GMAT is really a foreign language tests.
was the level randomly assigned?

In the question there was mention of "crust". As I don't eat pizzas, and don't know the details of what constitute pizzas, I might need to get a lesson on pizza preparation.
but I guess from the problem, crust n toppings are stuffs for making pizzas. right? if you order a pizza with four toppings, how many choices do u have?
what happened to crust plz!
And finally, what does "finally... extra-cheese as well as regular" mean?
Pizza eating guys please explain.
Thanks.

Hi,

Can you please tell me when do we have to use Combination Formula and when simple multiplication? Like in this case, I applied the formula 2C1 * 5C4 * 2C1
whereas its just simple multiplication

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

Write in simple terms what you need to do:

You need to choose 1 out of the 2 crusts AND choose 4 of the 5 toppings AND Choose one of the two cheese variants

Now write the value of each part in bold:

choose 1 out of the 2 crusts = 2c1
choose 4 of the 5 toppings = 5c4
choose one of the two cheese variants = 2c1

(Note: there is no step where you need to arrange anything)

Now, remember that AND refers to multiplication; OR refers to addition

Thus, our answer:

You need to choose 1 out of the 2 crusts AND choose 4 of the 5 toppings AND Choose one of the two cheese variants

= \(2c1 * 5c4 * 2c1\)

= \(2 * 5 * 2\)

= \(20\)

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