Question

Troy and Lisa were shopping for school supplies. Each purchased different quantities of the same notebook and thumb drive. Troy bought five notebooks and five thumb drives for $110. Lisa bought three notebooks and five thumb drives for $102. Find the cost of each notebook and each thumb drive.

Answer 1

Notebooks cost $4

Thumb drives cost $18

Explanation:

x=$ for notebooks

y=$ for thumb drives

5x + 5y = 110 ----> for Troy

3x + 5y = 102 ----> for Lisa

Use subtraction to find x.

(5x + 5y = 110)

-(3x + 5y = 102)

_____________

2x + 0y = 8

2x = 8

x=4

Sub 4 for x into 5x + 5y = 110

20 + 5y = 110

-20 -20

___________

5y = 90

y=18

Notebooks cost $4

Thumb drives cost $18