Question 31778
Let amount invested at 11.5% be "x".
Then amount invested at 12% must be "90000-x"
Interest on 11.5% investment is 11.5%(x)=0.115x
Interest on 12% investment is 12%(90000-x)=10800-0.12x
EQUATION:
 Interest + Interest = $10525
0.115x+10800-0.12x=10525
Mutiply by 1000 to get rid of the decimals:
115x + 10800000=120x=10525000
-5x=-275000
x=$55,000 (amount invested at 11.5%)
90,000-55,000= $35,000 (amount invested at 12%)

Cheers,
Stan H.