Question 1190050
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Assuming she pays back the money entirely before the 30 day period is up, then the only extra fee is the $17 per $100 mentioned.


She borrows $900 which means there are 900/100 = 9 lots of the 17. In other words, 9*17 = 153 is the processing fee paid on top of the $900 she needs to pay back.


That $153 covers 30 days.
If we're dealing with a 360 day year (some, if not most, banking formulas rely on this convention), then that's 30/360 = 1/12 of the year. So 12*153 = 1836 would cover the entire year if this rate is kept up.


Then divide this over the original amount borrowed
1836/900 = 2.04 = 204%


The annual rate is 204%
It's very common to have payday loans with such high APR. If anything, this is probably on the low end of the scale.  



If your teacher wants you to use a 365 day year, then the multiplier 365/30 will scale the $153 up to 153*(365/30) = 1861.50
Then we can say
1861.50/900 = 2.068 = 206.8% approximately
which isn't too far from the 204% APR calculated earlier.
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