Question

If the simple interest on ​$4000 for 8 years is ​$2880​, then what is the interest​ rate?

Answer 1

9%

Explanation:

To find the interest rate (r), you can use the formula for simple interest:

{Simple Interest} (SI) = (P*t*r)/{100}

Where:

- SI is the simple interest.

- P is the principal amount (initial amount) = $4000.

- r is the rate of interest (in percent) you're trying to find.

- t is the time period in years = 8 years.

Given that the simple interest is $2880, and the other values are known, you can set up the equation:

2880 = {4000*r*8}/{100}

Now, solve for r:

2880 = {32000r}/{100}

To isolate r, you can divide both sides by 32000/100, which simplifies to 320:

2880 = 320r

Now, divide both sides by 320:

r = {2880}/{320}

Simplify:

r = 9%

So, the interest rate is 9%.