Question

Walter and Brian each have a CD collection. • The number of CDs in Walter's collection can be represented by x. • The number of CDs in Brian's collection is 3 times the number in Walter's collection. • The total number of CDs in both collections is 144. What is x, the number of CDs in Walter's collection?

Answer 1

Number of CDs in Walter's collection = x = 36

Explanation:

x denotes number of CDs in Walter's collection.

Also, the number of CDs in Brian's collection is 3 times the number in Walter's collection.

Number of CDs in Brian's collection
`=3x`

Total number of CDs in both Walter's collection and Brian's collection = 144

`x+3x=144\\4x=144\\x=(144)/(4)\\ x=36`

So,

Number of CDs in Walter's collection = x = 36