
11th February 2009, 03:08 PM

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Sec 4 Mathematics, Hire Purchase
Qns: The cash price of an airconditioner was S$1800. Vernon bought it by paying monthly instalments of S$129 w/ zero downpayment, If the flat rate of interest is 6% p.a., find the no. of instalments he has to make before gaining ownership of the airconditioner.
this is how I did it:
6% x 1800 = S$108 + S$1800 = S$1908
S$129x12 = S$1548 which means he wont be able to finish paying for the air conditioner within the first year. hence, I add another year's interest.
S$1908 + S$108 = S$2016
S$2016S$1548 = S$468
S$468 / 129 = 3.6 round off to nearest no. = 4
4+12=16 therefore, Vernon has to make 16 instalments before gaining ownership of the air conditioner.
but the answer sheet states that the answer for this question is 15. why is that so?
please help!

 
11th February 2009, 03:40 PM

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Re: Sec 4 Mathematics, Hire Purchase
yup it is 15
interest = 1800 x6/100 = 108
total pay = 108 + 1800 = 1908
no.installment = 1908 / 129 =14.791 = 15(round off)
Last edited by Vikemen; 11th February 2009 at 03:41 PM.

 
11th February 2009, 03:44 PM

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Re: Sec 4 Mathematics, Hire Purchase

 
11th February 2009, 03:45 PM

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Re: Sec 4 Mathematics, Hire Purchase
seem like a easy Emath question

 
11th February 2009, 03:57 PM

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Re: Sec 4 Mathematics, Hire Purchase
Originally Posted by Vikemen yup it is 15
interest = 1800 x6/100 = 108
total pay = 108 + 1800 = 1908
no.installment = 1908 / 129 =14.791 = 15(round off)  i got the same answer as you
Last edited by skyangel; 11th February 2009 at 03:57 PM.

 
11th February 2009, 06:12 PM

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Re: Sec 4 Mathematics, Hire Purchase
Originally Posted by skyangel i got the same answer as you  but, S$129x12 = S$1548, which means that Vernon would not have been able to finish paying the full sum by the end of the 1st year, so shouldn't you add another year's interest?
S$1908 + S$108 = $2016
S$2016/129 = 15.6 = 16 when rounded off

 
11th February 2009, 06:16 PM

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Re: Sec 4 Mathematics, Hire Purchase
hire purchase price is different , it is not about years ,it is about the total cost interest

 
11th February 2009, 07:07 PM

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Re: Sec 4 Mathematics, Hire Purchase
Originally Posted by Vikemen hire purchase price is different , it is not about years ,it is about the total cost interest  yeah, the total cost of interest in this case is S$108 x2, S$216 'cos Vernon took 2 years to repay the loan.
correct?
if not, please do explain why. im super confused
btw, thanks uh vikemen, for bothering enough to reply. (: pastelpink added 1 Minutes and 17 Seconds later...
Originally Posted by pompomdidi Tis is O'lv Math?  haha, yeah.
e maths = elementary maths ma.
Last edited by pastelpink; 11th February 2009 at 07:08 PM.
Reason: Post Bumping

 
11th February 2009, 07:11 PM

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Re: Sec 4 Mathematics, Hire Purchase
OH shit. My teacher just went through this qns yesterday!!! I forgot to copy down the method to find it... I only know you nonid round off de...

 
2nd April 2009, 11:52 AM

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Re: Sec 4 Mathematics, Hire Purchase
Originally Posted by pastelpink Qns: The cash price of an airconditioner was S$1800. Vernon bought it by paying monthly instalments of S$129 w/ zero downpayment, If the flat rate of interest is 6% p.a., find the no. of instalments he has to make before gaining ownership of the airconditioner.
this is how I did it:
6% x 1800 = S$108 + S$1800 = S$1908 S$129x12 = S$1548 which means he wont be able to finish paying for the air conditioner within the first year. hence, I add another year's interest.
S$1908 + S$108 = S$2016
S$2016S$1548 = S$468
S$468 / 129 = 3.6 round off to nearest no. = 4
4+12=16 therefore, Vernon has to make 16 instalments before gaining ownership of the air conditioner.
but the answer sheet states that the answer for this question is 15. why is that so?
please help!  I suppose you nid 2 count the downpayment and interest together 1st before assuming he din have enough to pay for 1st yr.
__________________ The most fearful thing is fear itself. Be brave and face up the reality. 
 
2nd April 2009, 09:49 PM

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Re: Sec 4 Mathematics, Hire Purchase
u cannot round up got to round down

 
22nd April 2009, 11:14 PM

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Re: Sec 4 Mathematics, Hire Purchase
my understanding is 1,800*1.06/129 = approx 14.7 installments rounded up to 15.
total payment to be made = (1,800(principal) + 135(interest)) = 1,935
Number of installments = 1,935 / 129 = 15 exactly.
6% is interest per annum and its on a flat rate so i think u need to pro rate the interest payable.
anyway.. the answer will still be 15. only diff is the interest.

 
24th April 2009, 07:25 AM

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Re: Sec 4 Mathematics, Hire Purchase
first year = 1800 x 1.06 = 1908
since he is paying at 129 x 12 = 1548 in first year
second year he left (1908  1548) x 1.06 = 381.6
he need to pay 381.6 / 129 = 2.958 ~ 3
Therefore he need to pay 12 + 3 = 15 installments
Am I right?

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