Final answer:
Katie placed $20,000 into the loan with a 3% interest rate. This was calculated by setting up and solving a system of equations based on the given total amount of loans, the individual interest rates, and the total interest accrued in one year.
Step-by-step explanation:
The question relates to solving a system of equations based on simple interest formula to find the amount Katie put into the loan with a 3% interest rate. Using two loans totaling $50,000, with separate interest rates of 3% and 7%, and knowing that the total interest accrued in one year is $2,700, we can set up the following system of equations:
- Loan with 3% interest rate: 0.03x
- Loan with 7% interest rate: 0.07(50,000 - x)
- Total interest: 0.03x + 0.07(50,000 - x) = 2,700
By solving this equation, we can determine the amount placed in the loan with a 3% interest rate:
0.03x + 3,500 - 0.07x = 2,700
-0.04x = -800
x = $20,000
Hence, Katie put $20,000 into the loan with a 3% interest rate.