How many of each type of box is it carrying?

Question

A delivery truck is transporting boxes of two sizes: large and small. The large boxes weigh 60 pounds each, and the small boxes weigh 30 pounds each. There are 110 boxes in all. If the truck is carrying a total of 5100 pounds in boxes, how many of each type of box is it carrying?

Answer 1

L+S= 110

60L + 30S = 5100

30L + 30S = 3300 subtract to get

30L = 1800

L = 1800/30 = 60 large boxes

S = 110-60 = 50 small boxes

60(60) +30(50) = 3600+1500= 5100