# Thread: can you help me with finance math?

1. ## can you help me with finance math?

I have a mortgage of \$40.000. The term of duration is of 25 years, being applied interest rate of annual 12.5% being accumulated to the balance of debt nonamortized. The value of each quota is of \$ 436. With these data they ask to me to calculate the paid amount of the interest during the first three month.

2. ## hope this can help

N=3
I%=12.5/4
lond=-40000
repay each time (in your case 3 month)=436
Final amount needs to pay by end of 3 month = 42519.11

so the interest chared is 2519.11 for 3 month

3. Originally Posted by thechineseguy
N=3
I%=12.5/4
lond=-40000
repay each time (in your case 3 month)=436
Final amount needs to pay by end of 3 month = 42519.11

so the interest chared is 2519.11 for 3 month
You shouldn't post replies to a thread that has been flagged as a double post. Replies should be posted at the original thread, which is here: http://www.mathhelpforum.com/math-he...ance-math.html.

Threads now merges. CB

4. Originally Posted by gusty
I have a mortgage of \$40.000. The term of duration is 25 years, being applied interest rate of annual 12.5% being accumulated to the balance of debt nonamortized. The value of each quota is \$ 436. With these data they ask to me to calculate the paid amount of the interest during the firs three months
The interest rate for monthly repayments is $12.5/12$% (there are other ways of computing this depending on exactly what is mean by the annualy interest rate, but this is a common way).

Put

$r=(12.5/12)/100 \approx 0.01042$

Then after one month the remaing debt is:

$p_1=40000 (1+r)-436=39980.8$

after two month:

$p_2=p_1 (1+r)-436=39961.4$

after three month:

$p_3=p_2 (1+r)-436=39941.8$

So you have paid off $40000-39941.8=58.2$ dollars all the rest of the payments were for interest.

CB