Investment Problem

Question

Jolene invests her savings in two bank accounts, one paying 3 percent and the other paying 9 percent simple interest per year. She puts twice as much in the lower-yielding account because it is less risky. Her annual interest is 5655 dollars. How much did she invest at each rate?

Answer 1

Let x = the amount invested in investment product # 1.

Investment # 1: 9%*x = 0.09x

Investment #:2: 3%*x = 0.03*(2x)

0.09x + 0.03*(2x) = 5655

0.09x + 0.06x = 5655

0.15x = 5655

Divide both sides of the above equation by 0.015:

x = $37,700

2x = $75,400

Check:

0.09*37700 + 0.03*75400 = 3393 + 2262

= 5655

Answer 2

Set up an equation using x for the amount she invested at 9% (.09x) and 2x for the amount she invested at 3% (.03)(2x). Add them together and set them equal to $5655. Solve for x (and then 2x) for your answers.