Bailey uses his credit card to purchase accessories for his classic car. The only purchase he will make on his credit card is for the $3000 worth of accessories. He has a credit limit of $5000 with a 55-day interest-free period and interest of 17.65% p.a. His minimum payment is $25 or 3% of the balance, whichever is greater.

a) Bailey makes a regular payment of $250 at the end of each month with interest calculated daily and added to his balance at the end of month. How many months it will take him to pay off his credit card balance?
b) Bailey also has the option of taking out a personal loan for $3000 with flat rate interest of 15.40% p.a. for 2 years and regular monthly repayments of $163.50. Which option is the most cost effective for Bailey? Justify your answer using calculations.

Just need help with a, then should be able to figure out b, thanks.