An investment of 4300 was made one year ago.
Part of the investment was placed into an account paying s interest at 6 %
The remainder of the investment was placed into an account paying s interest at 9%
After one year, you received a total of 315 in interest. How much was invested in each account?
Calculate Principal Amounts for each fund:
For Fund 1, we invest an unknown amount, let us call it x
For Fund 2, the remaining principal is 4300 - x
Calculate Interest Credit for Fund 1
Since Fund 1 credits interest using the simple interest method, we have 0.06x
Calculate Interest Credit for Fund 2
Since Fund 2 credits interest using the simple interest method, we have 0.09(4300 - x)
Set up a grid with fund details:
| Interest Paid | Principal | Interest Rate | |
| Fund 1 | 0.06x | x | 6 % |
| Fund 2 | 0.09(4300 - x) | (4300 - x) | 9% |
| Total | 315 | 4300 | -- |
Calculate x from the grid:
Since both Interest paid columns add up to the total interest earned of 315, we set up an equation
0.06x + 0.09(4300 - x) = 315
0.06x + 387 - 0.09x = 315
387 - 0.03x = 315
Subtract 387 from each side:
387 - 387 - 0.03x = 315 - 387
Cancelling the 387 on the left side, we get:
-0.03x = -72
Divide each side by -0.03
| -0.03x | |
| -0.03 |
| = |
| -72 |
| -0.03 |
Cancelling the -0.03 on the left side, we get:
x = 2400 ← Fund 1 Investment
This means we should 4300 - 2400 = 1900 into Fund 2
Final Answer
1900 into Fund 2
