For the answer to the question above asking How much interest did you pay if you have a credit card with a balance of $1,256.34 and a 9.5% APR. A late payment fee of $29.00 is added to the principal if you pay after 5/28. You make a payment for $200.00 on 5/28.
int is about 1% per mo so is either 9.95 or 8.36
So the equation is
(1256.34 * .095/12) = ?
I don't have a calculator but you can solve it from that.