Cylinder J and Cylinder K have a total amount of 2033 mℓ of water. For Cylinder K and Cylinder L, the total amount of water is 4151 mℓ. The amount of water in Cylinder J is ⁴₇ the amount of water in Cylinder L. What is the average amount of water in the 3 cylinders?
Cylinder J = 4 u
Cylinder L = 7 u 

Cylinder K + Cylinder J = 2033 --- (1)
Cylinder K + Cylinder L = 4151 --- (2)

(2) - (1)
(Cylinder K + Cylinder J) - (Cylinder K + Cylinder L) = 4151 - 2033
7 u - 4 u = 2118
3 u = 2118

1 u = 2118 ÷ 3 = 706
Cylinder J = 4 u = 706 x 4 = 2824

Cylinder J + Cylinder K + Cylinder L = 2824 + 4151 = 6975 mℓ

Average amount of water in the 3 cylinders
= 6975 ÷ 3 
= 2325 mℓ

Answer(s): 2325 mℓ