Answer:
You can build 1296 different home theater systems.
Step-by-step explanation:
Fundamental counting principle:
States that if there are p ways to do a thing, and q ways to do another thing, and these two things are independent, there are p*q ways to do both things.
There are:
6 different TVs
12 types of surround sound systems.
18 types of DVD players.
How many different home theater systems can you build?
The components are independent, so, by the fundamental counting principle:
6*12*18 = 1296
You can build 1296 different home theater systems.