We know that
• The rate is 0.02 calories per pound each minute.
,
• There are 417 calories.
,
• Liz weighs 120 pounds.
First, we multiply the weight with the rate.
This means Liz burns 2.4 calories each minute. If there are 417 calories, we just have to divide.
Therefore, Liz would take 173.75 minutes to burn off the sandwich.