The answer is "$16.52".
APR of 15.25%
How much is charged in interest this month if her balance is $1,300
15.25% compounded monthly = 15.25/12 = 1.27083% monthly interest rate
1.27083% of $1,300 = 0.0127083 x 1300 = $16.52
thus, the amount charged in interest is $16.52.