If the total bill is $85, and you want to leave a 15% tip, then you can calculate it as follows:
85 * 15%
= 85 * 15/100
= 85 * 0.15
= 12.75
The amount that should be left as a tip is D. $12.75.
27.5 / 3.5 = 7.86; The average yearly snowfall was 7.86 inches.
Box a should have 30 pieces of chocolate and box b should have 20 pieces of chocolate