Cylinder J and Cylinder K have a total amount of 1968 mℓ of water. For Cylinder K and Cylinder L, the total amount of water is 4704 mℓ. The amount of water in Cylinder J is ³₇ the amount of water in Cylinder L. What is the average amount of water in the 3 cylinders?
Cylinder J = 3 u
Cylinder L = 7 u 

Cylinder K + Cylinder J = 1968 --- (1)
Cylinder K + Cylinder L = 4704 --- (2)

(2) - (1)
(Cylinder K + Cylinder J) - (Cylinder K + Cylinder L) = 4704 - 1968
7 u - 3 u = 2736
4 u = 2736

1 u = 2736 ÷ 4 = 684
Cylinder J = 3 u = 684 x 3 = 2052

Cylinder J + Cylinder K + Cylinder L = 2052 + 4704 = 6756 mℓ

Average amount of water in the 3 cylinders
= 6756 ÷ 3 
= 2252 mℓ

Answer(s): 2252 mℓ