how much was invested in each account?

Question

Maricopa's Success scholarship fund receives a gift of $ 85000. The money is invested in stocks, bonds, and CDs. CDs pay 3 % interest, bonds pay 3.5 % interest, and stocks pay 10.3 % interest. Maricopa Success invests $ 20000 more in bonds than in CDs. If the annual income from the investments is $ 4575 , how much was invested in each account? 

Answer 1

.103S + .035B + .03C = 4575

B=20000+C

.103S + .035(20000+C) +.03C = 4575

S=85000-B-C = 85000-20000-C-C= 65000-2C

.103(65000-2C) + .035(20000+C)+.03C =4575

-.206C +.035C +.03C = 4575-.035(20000) -.103(65000)

.141C = -4575 + 700+ 6695 = 2820

C = 2820/.141 = $20,000 invested in CD's

B = 20000+ C = $40,000 invested in Bonds

S = 85000-C-B = $25,000 invested in Stocks

.103(25K) +.035(40K) + .03(20K) = 2575 + 1400 + 600= 4575 (K=$1,000)