7 identical 10-cm cubes are placed in an empty rectangular tank of length 83 cm and width 23 cm. The tank is then filled with water from a tap flowing at a rate of 7 litres per minute. It takes 12 minutes to fill up ²₅ of the tank. What is the height of the tank? Correct your answer to 1 decimal place.
Volume of 1 cube
= 10 x 10 x 10
= 1000 cm³ 

Volume of 7 cubes
= 7 x 1000
= 7000 cm³ 

1 ℓ = 1000 mℓ
7 ℓ = 7000 mℓ

Volume of water in the tank
= 12 x 7000
= 84000 mℓ

Volume of ²₅ of the tank
= 84000 + 7000
= 91000 mℓ

Volume of the tank
= 91000 ÷ ²₅
= 91000 x ⁵₂
= 227500 mℓ

Base area
= 83 x 23
= 1909 cm² 

Height of the tank
= 227500 ÷ 1909
≈ 119.2 cm

Answer(s): 119.2 cm