Splitting investments. Joan had $3,000 to invest. She invested part of it in an investment paying 8% and the remainder in an investment paying 10%. If the total income on three investments was $290, than how much did she invest at each rate?

amount invested at 8% --- x

amount invested at 10% -- 3000-x

.08x + .10(3000-x) = 290
.08x + 300 - .1x = 290
-.02x = -10
x = -10/-.02 = 500

so $500 invested at 8% and 2500 invested at 10%

Investment. Part of $25,000

Well, let's figure this out, and hopefully, my answer will not be a joke!

Let's say Joan invested x dollars at 8%. So, the amount invested at 10% would be $3000 - x (since she invested the remainder).

Now, we can calculate the income from each investment. The income from the investment at 8% would be 8% of x, which is 0.08x. The income from the investment at 10% would be 10% of ($3000 - x), which is 0.1(3000 - x).

According to the problem, the total income from the investments is $290. Therefore, we can set up the following equation:

0.08x + 0.1(3000 - x) = 290.

Now, let's solve for x:

0.08x + 0.1(3000 - x) = 290
0.08x + 300 - 0.1x = 290
-0.02x = -10
x = -10 / (-0.02)
x = 500.

Hey, there we have it! Joan invested $500 at 8% and $2500 at 10%.

Now, that's no joke!

Let's assume Joan invested x dollars at 8% and (3000 - x) dollars at 10%.

The income from the investment at 8% is given by (x * 8%) = 0.08x dollars.
The income from the investment at 10% is given by ((3000 - x) * 10%) = 0.1(3000 - x) dollars.

According to the problem, the total income from the investments is $290, so:

0.08x + 0.1(3000 - x) = 290

Now we can solve for x.

0.08x + 0.1(3000 - x) = 290
0.08x + 300 - 0.1x = 290
-0.02x + 300 = 290
-0.02x = -10
x = -10 / -0.02
x = 500

Therefore, Joan invested $500 at 8% and ($3000 - $500) = $2500 at 10%.

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

Let's assume that Joan invested $x in the investment paying 8% and $(3000 - x) in the investment paying 10%.

According to the problem, the interest earned from the 8% investment can be calculated as 0.08x, and the interest earned from the 10% investment can be calculated as 0.1(3000 - x).

The total income from both investments is given as $290. So, we can write the equation:

0.08x + 0.1(3000 - x) = 290

Now, let's solve this equation step by step.

Distribute 0.1 to (3000 - x):

0.08x + 0.1(3000) - 0.1(x) = 290

Multiply 0.1 by 3000:

0.08x + 300 - 0.1x = 290

Combine like terms:

0.08x - 0.1x + 300 = 290

Combine the x terms:

-0.02x + 300 = 290

Subtract 300 from both sides:

-0.02x = -10

Divide by -0.02 to solve for x:

x = (-10) / (-0.02)

x = 500

Therefore, Joan invested $500 at a rate of 8% (0.08) and $(3000 - 500) = $2500 at a rate of 10% (0.1).