Loan repayments! (1 Viewer)

atakach99

Member
Joined
May 19, 2007
Messages
146
Gender
Male
HSC
2008
Mr and Mrs Jones mortgage their house for $50 000

a) Find the amount of the monthly repayments they will have to make if the mortgage is over 25 years, and if the interest on the mortgage is 14% p.a.

b) If they want to pay for their mortgage out after 15 years, what monthly repayment will they need to make?
 

eskimoh

Member
Joined
Oct 23, 2007
Messages
51
Gender
Female
HSC
2008
do u have answers?
i got
a) P= $531.79

and assuming that the same interest of 14%pa is charged for part 2,
b) $595.06 ??
 

crammy90

Member
Joined
Mar 26, 2006
Messages
264
Gender
Male
HSC
2008
atakach99 said:
Mr and Mrs Jones mortgage their house for $50 000

a) Find the amount of the monthly repayments they will have to make if the mortgage is over 25 years, and if the interest on the mortgage is 14% p.a.

b) If they want to pay for their mortgage out after 15 years, what monthly repayment will they need to make?
lol i tried
i) 598.82
ii) 663.19

i dont think there right tho as i do 598.82 X 300 mnths = some number like 180,000 aha and i dont think youd pay that much for a 50,000 loan but the rate is quiet high so i dno
if u want working i could aha
 

crammy90

Member
Joined
Mar 26, 2006
Messages
264
Gender
Male
HSC
2008
Timothy.Siu said:
wow all different answers =S

a)601.88
b)665.87
aha diversity!
did u use 14/12 = whatever (dont have calc) for the rate for each month
and then do it for 300 months?
 

eskimoh

Member
Joined
Oct 23, 2007
Messages
51
Gender
Female
HSC
2008
lol ill do my quick working out (or a basis of what i did) to show how i got my answer

a) let P = monthly repayment
month1 = 50 000 - P
month 2 = 50 000 -2P
.
.
.
month 12 or (A1) = 50 000 - 12P (1.14)
month 13 = [50 000 -12P (1.14)] -P
.
.
month 24 or (A2) = [(50 000(12P)(1.14)) - 12P] [1.14]
= 50000-12P(1.14)^2 - 12P(1.14)

.
.
.
.etc.
.
A25 (25th year) = 50 000-12P(1.14)^25 - 12P(1.14)^24 - ............... - 12P(1.14)
=50000(1.14)^25 -12P(1.14)^25 - 12P(1.14)^24 - .............-12P(1.14)

= 50 000(1.14)^25 - [12P(1.14)] (1(1.14)^25 -1)/(0.14) <---using a G.P SUM


at this time, the amnt left = 0 therefore

[12P(1.14)] (1(1.14)^25 -1)/(0.14) = 50 000 (1.14)^25
then solve and i got $ 531


b) i did the same for part b) except limiting it to 15 years
 

lyounamu

Reborn
Joined
Oct 28, 2007
Messages
9,989
Gender
Male
HSC
N/A
That's easy.

Just divide the percentage by 12 and get the numbers multiplied by 12.
 

Cleft

New Member
Joined
Sep 6, 2007
Messages
19
Location
Corndale
Gender
Male
HSC
2008
Yeah... how do you get that?

As the loan will be repayed after 25 years.
0 = 50 000(1.016^300) - M(1.0116^299 + 1.0116^288 + ... + 1.0116^1 +1)

Thus,
50 000(1.016^300) = M(1.0116^299 + 1.0116^288 + ... + 1.0116^1 +1)

Thus, M = 50 000(1.016^300) / (1.016^299 + 1.0116^288 + ... + 1.016^1 +1)

Now the denominator is a geometric series with a = 1, r = 1.0116 and n = 300

So, Sn = a(r^n - 1) / (r - 1)
= 1(1.0116^300 - 1) / (1.0116 - 1)

Now, that means that 50 000(1.0116^300) / Sn

M = $598.82


That's my working, can you point out where I went wrong?
 

Timothy.Siu

Prophet 9
Joined
Aug 6, 2008
Messages
3,449
Location
Sydney
Gender
Male
HSC
2009
Cleft said:
Yeah... how do you get that?

As the loan will be repayed after 25 years.
0 = 50 000(1.016^300) - M(1.0116^299 + 1.0116^288 + ... + 1.0116^1 +1)

Thus,
50 000(1.016^300) = M(1.0116^299 + 1.0116^288 + ... + 1.0116^1 +1)

Thus, M = 50 000(1.016^300) / (1.016^299 + 1.0116^288 + ... + 1.016^1 +1)

Now the denominator is a geometric series with a = 1, r = 1.0116 and n = 300

So, Sn = a(r^n - 1) / (r - 1)
= 1(1.0116^300 - 1) / (1.0116 - 1)

Now, that means that 50 000(1.0116^300) / Sn

M = $598.82


That's my working, can you point out where I went wrong?


umm from first glance i hope u didn't just use 1.016 because its 1.01666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666666
 

crammy90

Member
Joined
Mar 26, 2006
Messages
264
Gender
Male
HSC
2008
Cleft said:
Yeah... how do you get that?

As the loan will be repayed after 25 years.
0 = 50 000(1.016^300) - M(1.0116^299 + 1.0116^288 + ... + 1.0116^1 +1)

Thus,
50 000(1.016^300) = M(1.0116^299 + 1.0116^288 + ... + 1.0116^1 +1)

Thus, M = 50 000(1.016^300) / (1.016^299 + 1.0116^288 + ... + 1.016^1 +1)

Now the denominator is a geometric series with a = 1, r = 1.0116 and n = 300

So, Sn = a(r^n - 1) / (r - 1)
= 1(1.0116^300 - 1) / (1.0116 - 1)

Now, that means that 50 000(1.0116^300) / Sn

M = $598.82

That's my working, can you point out where I went wrong?

hah same as mine lol what we doing wrong aha
 

Cleft

New Member
Joined
Sep 6, 2007
Messages
19
Location
Corndale
Gender
Male
HSC
2008
Haha, seems they're right... I'll try it without terminating the decimal.

Yeah, that was the problem, use the repeating decimal and it comes out fine.
It's a bitch to put into a calculator though... grrr!
 
Last edited:

eskimoh

Member
Joined
Oct 23, 2007
Messages
51
Gender
Female
HSC
2008
ohhhhhh i see you didnt specify that the interest was calculated monthy so i took it as monthly repayments and yearly interst calculations
lol
but once i did it again i got timothys answers
 

Cleft

New Member
Joined
Sep 6, 2007
Messages
19
Location
Corndale
Gender
Male
HSC
2008
eskimoh said:
ohhhhhh i see you didnt specify that the interest was calculated monthy so i took it as monthly repayments and yearly interst calculations
lol
but once i did it again i got timothys answers

Not to be an ass or anything, but isn't that assumed with monthly repayments?
 

henry08

Active Member
Joined
Mar 13, 2008
Messages
1,174
Gender
Male
HSC
N/A
Lol at the 3 differernt answers in this thread with 2 people getting each answer. I'll work it out msyelf later.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top