Question

Katie invested a total of $6000 part at 3% simple interest and part at 4% simple interest at the end of one year the investment had earned $216 interest how much was invested at each rate?

Answer 1

• $3600 at 4%
• $2400 at 3%

Explanation:

Let x represent the amount invested at 4% (the higher rate). Then the amount invested at 3% is (6000-x), and the total interest earned is ...

0.04x + 0.03(6000 -x) = 216

0.01x +180 = 216 . . . . simpilfy

0.01x = 36 . . . . . . . . subtract 180

x = 3600 . . . . . . . . multiply by 100

6000-x = 2400

Katie invested $3600 at 4% and $2400 at 3%.