Carmen invests a total of $5200. Some of the money is invested at 8%. The rest is invested at 10%. If Carmen earned $496 of interest in one year, how much did she invest at each rate?

If x is invested at 8% then the rest (5200-x) is at 10%

so, add up the interest
.08x + .10(5200-x) = 496

To solve this problem, we can set up a system of equations based on the given information.

Let's assume that Carmen invested x dollars at 8% and (5200 - x) dollars at 10%.

The interest earned from the money invested at 8% can be calculated using the formula: Interest = Principal x Rate x Time. In this case, the rate is 8% (or 0.08) and the time is one year. So, the interest earned from the money invested at 8% is 0.08x.

Similarly, the interest earned from the money invested at 10% is 0.10(5200 - x).

According to the given information, Carmen earned a total of $496 in interest. Therefore, we can write the following equation:

0.08x + 0.10(5200 - x) = 496

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

0.08x + 0.10(5200 - x) = 496

0.08x + 520 - 0.10x = 496

0.08x - 0.10x = 496 - 520

-0.02x = -24

Dividing both sides of the equation by -0.02:

x = -24 / -0.02

x = 1200

Therefore, Carmen invested $1200 at 8% and $4000 (5200 - 1200) at 10%.