You would do 15/100 to turn the percentage into a decimal.
Then you would multiply 65.50 with .15.
65.5*.15=9.825
That would be the amount of money she got discounted.
In order to get the total, you would subtract the amount of money she got discounted by the original price.
65.5-9.825=55.675
If you round it you would get $55.68