I can not seem to get the correct answer for this questions. Please find the question and formula below.

Suppose your credit card balance is $15,000. The minimum payment is $311, and the annual percentage rate is 19.9%.

a.If you make a constant monthly payment of $311, how long will it take you to pay off the credit cardbalance? months(Round to four decimalplaces.)

b.How much interest will you pay if you elect to make the minimumpayment?

The generalized equation for finding the number of periods given the present value of an ordinary annuity is givenas:

n equals StartFraction ln left parenthesis StartStartStartFraction 1 OverOverOver 1 minus StartStartFraction PV times StartFraction i Over m EndFraction OverOver PMT EndEndFraction EndEndEndFraction right parenthesis Over ln left parenthesis 1 plus StartFraction i Over m EndFraction right parenthesis EndFraction

n=ln11PVimPMTln1+im

where

PMTequals

=the annual payment of an ordinary annuity

PVequals

=the present value of an ordinary annuity

i= the annual interest rate

n= the number of years

m= the number of compounding periods in a year