A punch recipe for half gallon (64 oz) of punch requires one pint (16 oz) of grape juice. How many quarts (1 qt = 32 oz) of grape juice are required for 2 1/2 gallons of punch?

Answer 1

2.5 gallons = 320 oz
punch : grape juice = 64 : 16 = 320 : g

64/16 = 320/g
4 = 320/g
4g = 320
g = 80

it would take 80 oz of grape juice
number of quarts = 80/32 = 2.5 quarts

(Editorial: Go metric to avoid such silly calculations)