An executive invests $21,000, some at 6% and the rest at 4% annual interest. If he receives an annual return of $1,240, how much is invested at each rate? at 6% interest at 4% interest

Answer 1

Let x = amount invested at 6%. Then, 21000 - x = amount invested at 4%.

0.06x + 0.04(21000 - x) = 1240

0.02x + 840 = 1240

0.02x = 400

x = 20000

Invest $20000 at 6% and $1000 at 4%.