The answer is as follows:
Add the portion spent for groceries or $132.48 to the portion spent on bills or $82.80. Then tis equals $215.28.
15% equals .15 because you move the decimal point to the left two places.
Then multiply .15 x the total from the two costs. Then multiply $215 x .15 or you get 215 x 132 = 22.680 and round up and move the decimal point to get the percent. 22.680