I'm always paying, never make it, but you can't look back

[venta]

So, sums. I can, broadly speaking, do sums. I have a degree in maths.

However, interest rate calculations have always baffled me. Sure, if you ask me to calculate 3 months compound interest at a monthly rate of x% I know what to do. However, when it comes to real examples of mortgages and credit cards, I can't work out what the sum I need to do is. I'm still slightly baffled about the interest charged me when I was a day late paying my credit card off in full in March.

Today, the BBC carried a story about a loanshark. It includes the following statement about someone who borrowed £1000:

"...to pay £49 a week over 60 weeks, making the total amount he had to
repay £2,940 at 917% APR."

Now, if we approximate 60 weeks to a year, then surely that's an annual interest rate of no more than 294%. The quoted APR isn't even in vaguely the right ballpark.

So... have I completely failed to understand APR ? (Wikipedia's page on the subject didn't really help with the definition.) Or is the BBC publishing unmitigated wank in the name of investigative journalism ?

Edit It turns out I'd failed to understand APR, and the BBC is cleared in this instance.

Comments

[chrisvenus]

Well, my final approach was even simpler than that:


chris@the:~$ factor 07775771223
7775771223: 3 11 19 37 571 587


[onebyone.livejournal.com]

Well if you knew that was there (which I didn't), why did you go looking for javascript versions? ;-)

[chrisvenus]

My google fu was weak. It threw up javascript ones only first. It was only when I realised how bad all the web based ones seemed that I realised you must have had a different way and googled further. I had assumed until your comment that my last method was the one you had used. :)