Question

Kathy has a total of 74 songs on cassettes and CDs in her music library. Each of her cassettes has 6 songs on it, and each

CD has 10 songs. If she has a total of 9 cassettes and CDs, how many of each does she have?

Answer 1

4 cassettes and 5 CDs

Explanation:

Create a system of equations

c is cassettes and d is CDs

6c+10d=74

c+d=9

I will use substitution

c=9-d

6(9-d)+10d=74

54-6d+10d=74

4d=20

d=5

Plug 5 back into the equation

c+5=9

c=4