Question 101137
.11X+.09(18000-X)=1820
.11X+1620-.09X=1820
.02X=1820-1620
.02X=200
X=200/.02
X=10000 INVESTED @ 11%
18000-10000=8000 INVESTED @9%
PROOF
.11*10000+.09*8000=1820
1100+720=1820
1820=1820