Question

You invested $9000 between two accounts paying 4% and 7% annual interest. If the total interest earned for the year was $510, how much was invested at each rate?

Answer 1

Let x represent the amount invested at 7%.

Then 9000-x is the amount invested at 4%

total interest earned is:

0.07x + 0.04(9000-x) = 510

0.07x + 360 - 0.04x = 510

0.03x = 150

x = 5000 the amount invested at 7%

9000 - 5000 = 4000 the amount invested at 4%