Question

Katie spent $465 on DVDs and CDs. The CDs cost $15 each, and the DVDs cost $19 each. A total of 27 CDs and DVDs were purchased. How many of each did she buy?

(solve by substitution or elimination methods only)

Answer 1

12 CDs and 15 DVDs

Explanation:

Let

x----> the number of CDs

y---> the number of DVDs

we know that

x+y=27 -----> x=27-y ----> equation A

15x+19y=465 ----> equation B

Solve by substitution

substitute equation A in equation B and solve for y

15(27-y)+19y=465

405-15y+19y=465

4y=465-405

4y=60

y=15 DVDs

Find the value of x

x=27-y

x=27-15=12 CDs