How to calculate this hire-purchase interest?

[sbasak]

A shop is offering good on hire-purchase scheme. They offered following two schemes.

Actual price: £ 499
Payable in 37 instalments of £ 25.09 each (ie. total payable £ 928.33)
Annual Percentage Rate of interest is 29.5%

Another scheme

Actual price: £ 399.99
Payable in 48 instalments of £ 11.8 each (ie. total payable £ 566.40)
Annual Percentage Rate of interest is 19.8%

My question is, how do they calculate the interest and montly payment?

Thanx

[opus]

?????
I normally would use the formula that goes by month, i.e. interest rate/12 is the monthly interest to be paid, so for the first month itit would be 499*(1+ (interest/(12*100)))-25.09.
The next month you use this value instead of the 499.
BUT, that would come to ZERO after 28 month???? So I'm lost, whre did you get those values?

[sbasak]

Many shops at UK (eg. Dixons, Comet etc.) sell goods at this method. In the leaflets they never describe how do they calculate the payment. I asked on stores personell, but they too can't explain it. I thought since there must be some mathematical formula behind it, I posted it in this forum.

Also, had they calculated the payment based on reducing rate of interest, monthly payment would have gone down every month.
Moreover, they are silent what they will charge if a customer decides to make full payment in between!

Do you think that they are pulling customers' legs?

[opus]

Do you think that they are pulling customers' legs?

YES,because the interestrate is from the moon and because I think the credit is payed for earlier then stated.

[sbasak]

I agree. Recently I saw a discussion on TV where it was telecast that many customers have complained that credit card interest statement is too confusining and they alleged that banks are charging more money than actual... !!!