Question 848569: tom invested some money at 5% and $300 more at 7%. His total annual interest income was $81. How much did tom invest at 5%? Answer by swincher4391(1107) (Show Source):
You can put this solution on YOUR website! .05x + .07*300 = 81
.05x + 21 = 81
.05x = 60
x = 1200
Unless the interpretation is that he invested $300 more than what he invested at 5%. I just feel like it should have said "more than the 5%"
Solving it this way:
.05x + .07(x+300) = 81
x = 500
Depends on what the interpretation is. I believe my original interpretation is what he meant. That is to say he took $1200 and put it into the 5% and then he took $300 more and put it into the 7%. The combination of the funds gives him the interest of $81.
