SOLUTION: Billy wants to invest 15000$, some at 5% and the rest at 10% interest. If he wants 8% yield on his money, how much should be invested at each rate?
Question 914695: Billy wants to invest 15000$, some at 5% and the rest at 10% interest. If he wants 8% yield on his money, how much should be invested at each rate? Answer by richwmiller(17219) (Show Source):
You can put this solution on YOUR website! 0.08*15000=$1200 interest earned on $15000 at 8%
Total amount of money invested: $15000
x+y=15000,
Total yearly interest for the two accounts is: $1200
0.05*x+0.1*y=1200
x=15000-y
Substitute for x
0.05*(15000-y)+0.1*y=1200
Multiply out
750-0.05*y+0.1*y=1200
Combine like terms.
0.05*y=450
Isolate y
y=$ 9000.00 at 10% earns $900 interest
x=15000-y
Calculate x
x=$ 6000.00 at 5% earns $300 interest
Check
0.05*6000+0.1*9000=1200
300+900=1200
1200=1200
If 1200=1200 is TRUE and neither x nor y is negative then all is well
codeint1