Question

Martha is carrying her biology, science, and math textbooks. Her books weigh a total of 9 pounds. Her biology textbook weighs 3 pounds and her math textbook weighs 40 ounces. How many ounces does her science textbook weigh?

Answer 1

1 pound = 16 oz
Her books weigh 9 pounds or (9)(16)= 144 oz
Math Textbook= 40 oz
Biology textbook= 3 pounds or (3)(16)= 48 oz

Total weight of books - math textbook - biology textbook = science textbook
144-40-48 = 56oz
science textbook = 56oz