Question

a self employed contractor nearing retirement made two investments totaling $ 15 ,000.In one year .These investments yielded $ 1,023 in simple interest .part of the money was invested at 6% and the rest at 7.5 %.How much was invested at each rate ?

Answer 1

let x and y represent your separate parts.
x+y=15000
x=15000-y
1.06x+1.075y=1023+15000
1.06(15000-y)+1.075y=1023+15000
53/50(15000-y)+1.075y=1023+15000
300(53)-1.06y+1.075y=16023
.0175y=16023-15900
.0175Y=123
1/100+3/400=120
7/400)Y=120