Answer:
$50,000 in stocks
$40,000 in bonds
$25,000 in CDs
Explanation:
Let c represent the amount invested in CDs. Then the amount invested in bonds is (c+15000) and the amount invested in stocks is (115000 -c -(c+15000)) = (100000 -2c). The total interest earned is ...
0.04c +0.053(c +15000) +0.062(100,000 -2c) = 6220
-0.031c +795 +6200 = 6220
-0.031c = -775 . . . . . . . . . . . . . . . subtract the left-side constants
c = 25000 . . . . . . . . . . divide by the coefficient of c
c+15000 = 40000 . . . . bonds
100000 -2c = 50000 . . . . . stocks
Maricopa Success invested ...
$50,000 in stocks
$40,000 in bonds
$25,000 in CDs