Question: I need help with this problem:
An ice cream factory makes 100 quarts of chocolate ice cream in 2 hours.  It can make 50 quarts of vanilla ice cream in 4 hours.  How many quarts in total would be made in 48 hours?
Answer: 
Chocolate ice cream can be made at 100 quarts / 2 hours = 50 quarts per hour.
Vanilla ice cream can be made at 50 quarts / 4 hours = 12.5 quarts per hour.
In 48 hours there would be 48 * 50 quarts = 2400 quarts of chocolate ice cream.
In 48 hours there would be 48 * 12.5 quarts = 600 quarts of vanilla ice cream.
Combined there would be 2400 chocolate + 600 vanilla = 3000 quarts of ice cream.