Beverage Dispenser E and Beverage Dispenser F have a total amount of 1090 mℓ of water. For Beverage Dispenser F and Beverage Dispenser G, the total amount of water is 1542 mℓ. The amount of water in Beverage Dispenser E is ³₇ the amount of water in Beverage Dispenser G. What is the average amount of water in the 3 beverage dispensers?
Beverage Dispenser E = 3 u
Beverage Dispenser G = 7 u 

Beverage Dispenser F + Beverage Dispenser E = 1090 --- (1)
Beverage Dispenser F + Beverage Dispenser G = 1542 --- (2)

(2) - (1)
(Beverage Dispenser F + Beverage Dispenser E) - (Beverage Dispenser F + Beverage Dispenser G) = 1542 - 1090
7 u - 3 u = 452
4 u = 452

1 u = 452 ÷ 4 = 113
Beverage Dispenser E = 3 u = 113 x 3 = 339

Beverage Dispenser E + Beverage Dispenser F + Beverage Dispenser G = 339 + 1542 = 1881 mℓ

Average amount of water in the 3 beverage dispensers
= 1881 ÷ 3 
= 627 mℓ

Answer(s): 627 mℓ