A delivery truck is transporting boxes of two sizes: large and small. The combined weight of a large box and a small box is 70 pounds. The truck is transporting 65 large boxes and 70 small boxes.

Question

If the truck is carrying a total of 4650 pounds in boxes, how much does each type of box weigh?

Answer 1

We know that 1 Large + 1 Small box = 70 lbs. So that means 65 Large and 65 Small boxes have a weight of

65 x 70 = 4550 lbs. Total weight of 65 Large and 70 Small boxes = 4650 lbs. That means that the remaining 5 Small boxes weigh 100 lbs (4650 - 4550 = 100). If 5 Small boxes weigh 100 lbs, then 1 Small box weighs 100/5 = 20 lbs. That leaves the Large box weighing 50 lbs.

To check these answers: 65 x 50 lbs + 70 x 20 lbs. = 3250 + 1400lbs = 4650 lbs.

Answer 2

65 combinations of one large and one small weighs 4550 lbs.

Therefore the additional 5 small boxes weigh 100 lbs., or 20 lbs each.

Can you now determine the weight of a large box?