Question

Troy and Lisa were shopping for school supplies. Each purchased different quantities of the same notebook and thumb drive. Troy bought 4 notebooks and 11 thumb drives for $233. Lisa bought 12 notebooks and 15 thumb drives for $357. Find the cost of each notebook and each thumb drive.

Answer 1

• notebook: $6
• thumb drive: $19

Explanation:

Let n and t represent the cost of a notebook and thumb drive, respectively. Then the two purchases can be represented by the equations ...

4n +11t = 233

12n +15t = 357

Subtracting the second equation from 3 times the first gives ...

3(4n +11t) -(12n +15t) = 3(233) -(357)

18t = 342

t = 342/18 = 19

Putting this into the first equation gives ...

4n +11(19) = 233

4n = 24

n = 6

The cost of each notebook was $6. Each thumb drive cost $19.