Afruit company delivers its fruit in two types of boxes: large and small. a delivery of 2 large boxes and 5 small boxes has a total weight of 67 kilograms. a delivery of 8 large boxes and 3 small boxes has a total weight of 166 kilograms. how much does each type of box weigh?

If a large box weighs x kgs and a small box weighs y kgs, we get 
2x+5y=67
8x+3y=166

Multiplying the first equation by -4 and adding it to the second, we get
-17y=-102. Dividing both sides by -17, we get y=6. Plugging it into the first equation , we get 2x+30=67 and 2x=37. Dividing by 2, x=18.5