Question

a delivery truck is transporting boxes of two sizes: large and small. The combined weight of a large box and a small box is 90 pounds. The truck is transporting 70 large boxes and 65 small boxes. If the truck is carrying a total of 6150 pounds in boxes, how much does each type of box weigh?

Answer 1

A small box weighs 30 lb; a large box weight 60 lb.

Explanation:

Let L = weight of large box

Let S = weight of small box

"The combined weight of a large box and a small box is 90 pounds."

L + S = 90

"The truck is transporting 70 large boxes and 65 small boxes. If the truck is carrying a total of 6150 pounds in boxes"

L = 90 - S Equation 1

The truck carries 65 small boxes and 65 large boxes and another 5 large boxes.

65(90) + 5(90 - S) = 6150 Equation 2

We use these two equations (Eq. 1 and Eq. 2) as a system of equations.

L = 90 - S

5850 + 450 - 5S = 6150

6300 - 5S = 6150

-5S = -150

S = 30

L = 90 - S = 90 - 30 = 60

S = 30; L = 60

Answer 2

45

Explanation:

70 + 65 = 135 boxed both large and small.

6150 / 135 = 45 pounds estimated.