Thomas charged $2,400 on his credit card to buy furniture. The interest rate charged by the credit card company is 24.9%. How much will he pay in interest after one month?
i=prt Interest = principal X rate X time You are asking for interest so lets fill in all the variables.
i=2400X.249X(1/12) I used .249 for rate because you convert the interest rate to a decimal. I used 1/12 for time because you only need 1 month and time is based off of a year. For example, if you wanted to know how much interest after 3 months you would use (3/12) Now solve. i=2400X.249X.0833333 i=49.80 Your interest after one month is $49.80