Solve the problem.

-Walt made an extra $7000 last year from a part-time job. He invested part of the money at 9% and the rest at 10%. He made a total of $660 in interest. How much was invested at 10%?
A) $3500
B) $3000
C) $4000
D) $5000

Question

Solve the problem.

-Walt made an extra $7000 last year from a part-time job. He invested part of the money at 9% and the rest at 10%. He made a total of $660 in interest. How much was invested at 10%?
A) $3500
B) $3000
C) $4000
D) $5000

Quizplus · Accepted Answer

Let x be the amount invested at 9%, then (7000 - x) is the amount invested at 10%. The equation for the total interest is: 0.09x + 0.10(7000 - x) = 660. Solving this equation gives x = 4000, so the amount invested at 10% is 7000 - 4000 = 3000.

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