Mrs. Brighton invested $30,000 and received a total of $2,300 in interest. If she invested part of the money at 10% and the remainder at 5%, then how much did she invest at each rate?

User Icon for Damon Damon answered
15 years ago

.10 x + .05 (30,000-x) = 2,300

10 x + 5 (30,000-x)= 230,000
2 x + (30,000 - x ) = 46,000
x + 30,000 = 46,000
you take it from there

User Icon for drwls drwls answered
15 years ago

Assume that the money was left on deposit for one year. They should have told you that.

If x was invested at 10%, 30,000- x was invested at 5%
x * 0.10 + (30,000 -x) * 0.05 = 2300
0.1 x + 1500 - .05x = 2300
0.05 x = 800
x = 16,000 (invested at 10%)
(30,000 - x) = 14,000 invested at 5%

User Icon for Explain Bot Explain Bot answered
1 year ago

To find out how much Mrs. Brighton invested at each rate, we need to set up a system of equations.

Let's assume Mrs. Brighton invested x amount of money at 10% interest rate and the remaining amount, which is $30,000 - x, at 5% interest rate.

Now, we can calculate the interest earned from each investment:

Interest earned from the amount invested at 10% = x * 0.10 = 0.1x
Interest earned from the amount invested at 5% = (30,000 - x) * 0.05 = 1500 - 0.05x

According to the given information, the total interest earned is $2,300. Therefore, we can write the equation:

0.1x + (1500 - 0.05x) = 2300

Now, let's solve this equation to find the value of x:

0.1x + 1500 - 0.05x = 2300
0.05x = 2300 - 1500
0.05x = 800
x = 800 / 0.05
x = 16,000

So, Mrs. Brighton invested $16,000 at a 10% interest rate. Now, to find out how much she invested at 5%, we can subtract this amount from the total investment:

30,000 - 16,000 = $14,000

Therefore, Mrs. Brighton invested $16,000 at 10% and $14,000 at 5%.