Question

Antonio is buying a stereo, speakers, and amplifiers for his car audio system. He is choosing among 4 models of stereos and 3 styles of speakers. If he has 36 different choices, how many kinds of amplifiers must there be?

2
3
4
12

Answer 1

The answer of the question is 3

Answer 2

Let the number of kinds of amplifiers be "a".

Antonio has 4 choices for the stereo and 3 choices for the speakers. Therefore, the total number of different choices he can make is:

4 (choices of stereos) x 3 (choices of speakers) x a (choices of amplifiers) = 12a

We are given that he has 36 different choices, so:

12a = 36

Dividing both sides by 12, we get:

a = 3

Therefore, there must be 3 kinds of amplifiers.

The answer is (B) 3.