jayshree invested $13,500 in two accounts, one paying 6% simple interest, and the other paying 8%. she received $990 in interest in a year how much did she invest at each rate

Question

This is a question on a homework assignment that I can't figure out. I'm not sure how to set up the equation

Answer 1

a + b = 13500

0.06a + 0.08b = 990

a = 13500 - b

0.06(13500 - b) + 0.08b = 990

810 - 0 06b + 0.08b = 990

0.02b = 180

b = $9000

I bet you can find a. Go!