A person invest $4000, part at 8.5 per annum and part at 9.5. At the end of the the year the 8.5 made $16 more. How much was invested at 9.5?

Let the amount invested at 8.5% be x

then the amount invested at 9.5% is 4000-x

solve for x

.085x - .095(4000-x) = 16
times 1000
85x - 95(4000-x) = 16000
....
....

the 9.5% investment is 4000-x

Let's assume the amount invested at 8.5% is x dollars.

Therefore, the amount invested at 9.5% is (4000 - x) dollars.

According to the given information, the investment at 8.5% earned $16 more than the investment at 9.5%.

So, we can set up the equation:

0.085 * x = 0.095 * (4000 - x) + 16

Now, let's solve the equation step-by-step:

0.085 * x = 0.095 * 4000 - 0.095 * x + 16

Multiply the decimals by their respective numbers:

0.085x = 380 - 0.095x + 16

Combine the "x" terms:

0.085x + 0.095x = 380 + 16

0.18x = 396

Divide both sides of the equation by 0.18:

x = 396 / 0.18

x ≈ 2200

So, approximately $2200 was invested at 8.5%.

Since the total investment was $4000, the amount invested at 9.5% is:

4000 - 2200 ≈ $1800

Therefore, approximately $1800 was invested at 9.5%.

To solve this problem, let's assume that the amount invested at 8.5% is x dollars. Since the total amount invested is $4000, the amount invested at 9.5% would be $4000 - x dollars.

Now, we can calculate the interest earned on each investment. The interest on the investment at 8.5% can be found using the formula:

Interest_1 = (x * 8.5%) / 100

Similarly, the interest on the investment at 9.5% is given by the formula:

Interest_2 = ((4000 - x) * 9.5%) / 100

According to the problem, the 8.5% investment made $16 more in interest than the 9.5% investment.

So, we can set up the equation:

Interest_1 - Interest_2 = $16

Substituting the formulas for the interest, we have:

((x * 8.5%) / 100) - (((4000 - x) * 9.5%) / 100) = $16

Now, let's solve this equation to find the value of x, which represents the amount invested at 8.5%.

Multiply both sides of the equation by 100 to eliminate the denominators:

(x * 8.5%) - ((4000 - x) * 9.5%) = $1600

Since the percentages are being multiplied by x and (4000 - x), let's multiply everything out:

0.085x - 0.095(4000 - x) = $1600

Distribute and simplify:

0.085x - 0.095(4000) + 0.095x = $1600

0.085x - 0.095 * 4000 + 0.095x = $1600

0.085x - 380 + 0.095x = $1600

Combine like terms:

0.180x - 380 = $1600

Add 380 to both sides:

0.180x = $1980

Divide both sides by 0.180 to solve for x:

x = $1980 / 0.180 ≈ $11,000

So, approximately $11,000 was invested at 8.5%, and the remaining amount, $4000 - $11,000 = -$7,000 (negative value), should have been invested at 9.5%.

It appears that there was an error in the problem or the given information is incorrect since it doesn't make sense to invest a negative amount of money.