Cylinder X and Cylinder Y have a total amount of 2185 mℓ of water. For Cylinder Y and Cylinder Z, the total amount of water is 2469 mℓ. The amount of water in Cylinder X is ³₅ the amount of water in Cylinder Z. What is the average amount of water in the 3 cylinders?
Cylinder X = 3 u
Cylinder Z = 5 u 

Cylinder Y + Cylinder X = 2185 --- (1)
Cylinder Y + Cylinder Z = 2469 --- (2)

(2) - (1)
(Cylinder Y + Cylinder X) - (Cylinder Y + Cylinder Z) = 2469 - 2185
5 u - 3 u = 284
2 u = 284

1 u = 284 ÷ 2 = 142
Cylinder X = 3 u = 142 x 3 = 426

Cylinder X + Cylinder Y + Cylinder Z = 426 + 2469 = 2895 mℓ

Average amount of water in the 3 cylinders
= 2895 ÷ 3 
= 965 mℓ

Answer(s): 965 mℓ