Some friends tell you that they paid $28146 down on a new house and are to pay $637 per month for 30 yrs. The selling price of the house is $137,897.81 . How much interest will they pay in 30 years?

Question

ramennoodle01 · Answer

I multipled and subtracted ($637x12x30) - $137,897.81 but the answer wasn't right

kittiwitti1 · Answer

http://www.thecalculatorsite.com/articles/finance/compound-interest-formula.php

ramennoodle01 · Answer

@kittiwitti1 
So the formula I'd use would be A = P (1 + r/n)^nt ?

kittiwitti1 · Answer

Yup

ramennoodle01 · Answer

@kittiwitti1
I'm still lost lol 
Is 
A= 137897.81
P=637
nt= 12(30)

kittiwitti1 · Answer

Did you calculate with that information?

ramennoodle01 · Answer

i got 3507.72

kittiwitti1 · Answer

Is it correct?
Sorry, I'm working on another subject at the moment.

ramennoodle01 · Answer

I forgot to mention that the rate was 5.7% compounded monthly

ramennoodle01 · Answer

No it isn't :(
It's okay lol

kittiwitti1 · Answer

Seems like you included that in the $t$ part

ramennoodle01 · Answer

wouldn't t= years?

kittiwitti1 · Answer

I meant $n$... please don't kill me ;-;

ramennoodle01 · Answer

I did 637(1 + (0.57/12))^(12*30)

kittiwitti1 · Answer

Odd. That should've worked.

ramennoodle01 · Answer

i was told that it would be (637*m*t) -$137,897.81 but it isn't giving me the correct answer

kittiwitti1 · Answer

@.Sam.

kittiwitti1 · Answer

Sorry. I'd help but I'm in a hurry and I don't want to abandon you... ahah

kittiwitti1 · Answer

Good luck~ ; -;

ramennoodle01 · Answer

@kittiwitti1 Thank you for all your help!

ramennoodle01 · Answer

@mathmate

ramennoodle01 · Answer

@jhonyy9

mathmate · Answer

`Some friends tell you that they paid $28146 down on a new house and are to pay $637 per month for 30 yrs. The selling price of the house is $137,897.81 . How much interest will they pay in 30 years? `

you answered
`I multipled and subtracted ($637x12x30) - $137,897.81 but the answer wasn't right`
It is almost right.
except that the mortgage is for (137,897.81-downpayment).  So you need to subtract this amount instead of 137,897.71.

ramennoodle01 · Answer

@mathmate So I would subtract 137,897.71 from $28,146 first and then use the formula I started with (637x12x30)?

mathmate · Answer

`So I would subtract 137,897.71 from $28,146 first and then use the formula I started with (637x12x30)?`

House price: 137,897.71
downpayment:28,146
So he borrowed:137,897.71-28,146  (not the other way round).
After that, you can use the method you started with, i.e. subtract amount borrowed FROM the total of the payments.