A $136000 trust is to be invested in bonds paying 8%, CDs paying 7%, and mortgages paying 10%. The bond and CD investment must equal the mortgage investment. To earn a $12040 annual income from the investments, how much should the bank invest in bonds?

Answer 1

Let x = amount in bonds
Then 68000-x is the amount in CDs

Now just add up the interest:

.08x + .07(68000-x) + .10*68000 = 12040