Solve.
-How can $42,000 be invested, part at 4% annual simple interest and the remainder at 10% annual simple interest, so that the interest earned by the two accounts is equal at the end of the year?
A) $30,000 invested at 4%; $12,000 invested at 10%
B) $22,000 invested at 4%; $20,000 invested at 10%
C) $20,000 invested at 4%; $22,000 invested at 10%
D) $12,000 invested at 4%; $30,000 invested at 10%

Question

Quizplus · Accepted Answer

Let the amount invested at 4% be $x. Then, the amount invested at 10% is $42,000 - $x. The interest from the first investment is 0.04x, and from the second investment is 0.10(42,000 - x). Setting these equal to each other because the interests are equal: 0.04x = 0.10(42,000 - x). Solving this equation gives x = $30,000 at 4%, and thus $12,000 at 10%.

Solve. -How Can $42,000 Be Invested, Part at 4% Annual Simple