How do I calculate future credit card interest rate with inflation?

Hi all!

I am trying to figure out what calculation I need to learn to be able to work out the above question.

My example I have been given is:

I am not understanding how to work this out.

I have 2 credit cards:
one at $22,000 at 18% annual interest and another at $5000 at 22% annual interest.

This year I paid interest of $3770.00 (for both credit cards)

It is important that I add annual inflation (at 3%) on the balance owing from the items I purchased, and then I need to re-calculate interest on this new balance - i.e. next year my interest owing will expected to be $5212.

My Question is: How was the above worked out?
I really need to understand this, as I must use the calculation to project 5 years of these credit card examples. i.e. interest charged in 2014/15 will be $5212, I then need to work out 2015/2016, 2017/2018 up until 18/19.

I am not looking for my work to be done for me, honest. I am simply wanting to understand this, as I really have tried and tried to work this out using different calculations and I simply do not get it.

Apologies for the long question;

Thank you in advance.