# Thread: Intrest rate problem?

1. Its for my bf
He has a 4000.00 dollar loan with 9% interest 8 months annually how much would he owe?

I have no idea how to do these problems

thanx

ph yea its a student loan

2. Originally Posted by tiffieblah
Its for my bf
He has a 4000.00 dollar loan with 9% interest 8 months annually how much would he owe?

I have no idea how to do these problems

thanx

ph yea its a student loan
check out Compound interest - Wikipedia, the free encyclopedia

you need to use this formula

$Amount = amount to borrow * (1 + interest rate)^time$

I would say that if the interest is calcualted monthly then the amount that he would owe would be

$Amount = 4000 * (1 + \frac{0.08}{12})^8$

I calculate that the Amount would be $4218.38 3. If you simply need an approximate: 4000 * .09 / 12 =$30 interest each month

4. Originally Posted by Wilmer
If you simply need an approximate:
4000 * .09 / 12 = \$30 interest each month
I'm having a drink :P

5. So shall I