Question

Genevieve is buying a car audio system that consists of a stereo, speakers, and amplifiers. She is choosing between 5 types of stereos and 2 types of amplifiers. If she has a total of 30 choices, how many types of speakers must there be?

A.3
B.6
C.10
D.20

Answer 1

I think the answer would be three because if you multiply all of the numbers together you get 30.

Answer 2

Answer: The answer is A.

The total choices are calculated by the product of the options in each case.

here she has 5 types of stereos and 2 types of amplifiers, with this two items genevieve gets 10 combinations.

If we also add the speakers, let's suppose we get x options for the speakers, and the problem says that the total options are 30, so 10*x = 30

dividing by 10, we get x = 3.

so there are 3 options for speakers, and the correct answer is A.