Beverage Dispenser L and Beverage Dispenser M have a total amount of 1799 mℓ of water. For Beverage Dispenser M and Beverage Dispenser N, the total amount of water is 4853 mℓ. The amount of water in Beverage Dispenser L is ⁴₇ the amount of water in Beverage Dispenser N. What is the average amount of water in the 3 beverage dispensers?
Beverage Dispenser L = 4 u
Beverage Dispenser N = 7 u 

Beverage Dispenser M + Beverage Dispenser L = 1799 --- (1)
Beverage Dispenser M + Beverage Dispenser N = 4853 --- (2)

(2) - (1)
(Beverage Dispenser M + Beverage Dispenser L) - (Beverage Dispenser M + Beverage Dispenser N) = 4853 - 1799
7 u - 4 u = 3054
3 u = 3054

1 u = 3054 ÷ 3 = 1018
Beverage Dispenser L = 4 u = 1018 x 4 = 4072

Beverage Dispenser L + Beverage Dispenser M + Beverage Dispenser N = 4072 + 4853 = 8925 mℓ

Average amount of water in the 3 beverage dispensers
= 8925 ÷ 3 
= 2975 mℓ

Answer(s): 2975 mℓ