A credit card's interest rate is the price one pay for borrowing money. This is called the annual percentage rate (APR).The Interest paid can be calculated by the formula I=PTR ÷ 100
Where P = Principal amount ,R= rate of interest in years.T= time.
P=$1,300 ,R= 20% T= year.
Substituting these values :
I= 1300 x 20 x1 ÷100
I= 260. He will pay an interest of 260÷12= $21.7 per month.
