Question

Problem Page Last year, Donna had $30,000 to invest. She invested some of it in an account that paid 9% simple interest per year, and she invested the rest in an account that paid 6% simple interest per year. After one year, she received a total of $1950 in interest. How much did she invest in each account?

Answer 1

The money invested in the account 1 was $25,000 and in the account 2 was 5,000.

Explanation:

In this case we can formulate a system of equations that could find the amount invested in each account, this is:

Money invested in the account 1 is A

Money invested in the account 2 is B

Eq. 1:
`A+B=30,000`

Eq. 2:
`(9)/(100) *A+(6)/(100) *B=1,950`

Replacing the equation 1 in 2, this is:

`(9)/(100) *(30,000-B)+(6)/(100) *B=1,950</p><p>Clearing the value of B:</p><p>[tex]2,700-0.09B+0.06B=1,950`

`2,700-1,950=0.09B-0.06B`

`750=0.03B`

`B=(750)/(0.03)`

`B=25,000`

Now, we can find A:

`A=30,000-B\\A=30,000-25,000\\A=5,000`

The money invested in the account 1 was $5,000 and in the account 2 was 25,000.