A delivery truck is transporting boxes of two sizes: large and small. the combined weight of a large box and a small box is 60 pounds. the truck is transporting 65 large boxes and 70 small boxes. if the truck is carrying a total of 4000 pounds in boxes, how much does each type of box weigh?

Let a = weight of large box in pounds

Let b = weight of small box in pounds

(1) 65a + 70b=4000

(2) a+b=60

Now we can simultaneously solve these equations.

a = 60 - b. Hence 65 (60 - b) + 70b = 4000 So 3900 + 5b = 4000 and 100 = 5b hence b = 20.

SImilarly a = 40. Now we can verify too by putting in the calculated values.