Solve the problem.
-Walt made an extra $7000 last year from a part-time job. He invested part of the money at 7% and the rest at 10%. He made a total of $580 in interest. How much was invested at 10%?
A)$5000
B)$4000
C)$3500
D)$3000

Question

Quizplus · Accepted Answer

Let x be the amount invested at 10%. Then, the amount invested at 7% is $7000 - x. The total interest is given by 0.07($7000 - x) + 0.10x = $580. Solving this equation, we find x = $3000.

Solve the Problem. -Walt Made an Extra $7000 Last Year from a Part-Time