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

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 70

pounds. The truck is transporting 60

large boxes and 55

small boxes. If the truck is carrying a total of 4050

pounds in boxes, how much does each type of box weigh?      

Answer 1

Let b = big box and s = small box. Here's what we know:

b + s = 70 (together, one of each box totals 70 pounds)

60b + 55s = 4050 (the truck is delivering 60 big and 55 small boxes, totaling 4050 pounds)

 

Let's use substitution to solve this. Isolate s in the first equation, and then plug in the value into the second:

s = 70 - b

60b + 55(70 - b) = 4050

Distribute:

60b + 3850 - 55b = 4050

simplify:

5b + 3850 = 4050

Subtract 3850 from both sides:

5b = 200

 

You should be able to find the large boxes from here, then use that to find the small ones' weights.