A scholarship fund raised $7000 in contributions. Part was invested in bonds paying 6% interest, and the rest was invested in bank certificates paying 8 ½%. It the total annual income is $520, find the amount invested at each rate.

Answer 1

part invested at 6% ---- x
part invested at 8.5% ---- 7000-x

.06x + .085(7000-x) = 520
.06x + 595 - .085x = 520
-.025x = -75
x = 3000

so $3000 invested at 6%, $4000 at the other rate