Math Help Please!?

Question

Malina can bring up to four CDs on a car ride. How many different ways can she brings no CDs? one CD? two CDs? three CDs? four CDs?

If you don't know the answers but know how to do it.....just help me anyways....I really need to aunderstand what the question means and how can it be solved....

Answer 1

Is the question that Malina can bring no CDs, 1 CD, 2 CDs, 3CDs, or 4 CDs, so what are the possible combinations she can choose?  Imagine the CDs are named 1, 2, 3, 4,  

What are the possible combinations she can choose if she takes 4 CDs?  There's only one combination because she's taking all four.  

What are the possible combinations she can choose if she takes 3 CDs?  She can take 1, 2, and 3.  She can take 1,2,4.  She can take 1,3,4.  She can take 2,3,4.   That's four combinations.

What if she takes 2 CDs?  1,2 or 1,3 or 1,4 or 2,3 or 2,4 or 3,4.  That's six combinations.

What if she takes 1 CD?  There's four choices.

If she takes none, there's only one way to take none.