Question

you have a credit card with a balance of $1256.34 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. How much interest did you pay?

Answer 1

you wold take 200.00 out of your balance and then multiply by 9.5% and that is your answer 

Answer 2

The interest paid will be $9.946 ≈ $9.95.

Explanation:

p = 1256.34

r =
`9.5/12/100=0.007917` (monthly)

Now, given is :

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.

As the payment is made on the last date, so no extra charge will be paid. So, it is simple interest of
`1256.34*0.007917=9.946`

Hence, the interest paid will be $9.946 ≈ $9.95.