Using simple interest, it is found that:
- The amount invested at 7% is $2,000.
- The amount invested at 8% is $8,000.
Simple interest is used when there is a single compounding per time period.
The interest after t years in is modeled by:
In which:
- P is the initial amount.
- r is the interest rate, as a decimal.
In this problem:
- A total of $10,000 was invested, hence
.
- Two accounts paying 7% and 8% annual interest, respectively, hence
.
- The total interest earned for the year was $780, hence
Then:
Considering :
Considering :
Considering :
And:
Then:
- The amount invested at 7% is $2,000.
- The amount invested at 8% is $8,000.
You can learn more about simple interest at brainly.com/question/25296782