Hey guys, got a math problem here. Teacher didn't give us anything on how to do it, and algebra was years ago. Here is the problem:

"Dimitri wants to buy a stereo for 650 dollars and pay for it using a credit card that has an Annual Percentage Rate of 19.8% and a periodic interest rate of 1.65%. Dimitri pays a minimum monthly payment of $21.45"

Question 1: How long will it take him to pay for the stereo?

Question 2: What is the total amount Dimitri will pay for the stereo?

Question 3: What is Dimitri's total cost of using credit?

I have no idea where to even start. Thanks.