6 identical 7-cm cubes are placed in an empty rectangular tank of length 80 cm and width 30 cm. The tank is then filled with water from a tap flowing at a rate of 6 litres per minute. It takes 8 minutes to fill up ¹₄ of the tank. What is the height of the tank? Correct your answer to 1 decimal place.
Volume of 1 cube
= 7 x 7 x 7
= 343 cm³ 

Volume of 6 cubes
= 6 x 343
= 2058 cm³ 

1 ℓ = 1000 mℓ
6 ℓ = 6000 mℓ

Volume of water in the tank
= 8 x 6000
= 48000 mℓ

Volume of ¹₄ of the tank
= 48000 + 2058
= 50058 mℓ

Volume of the tank
= 50058 ÷ ¹₄
= 50058 x ⁴₁
= 200232 mℓ

Base area
= 80 x 30
= 2400 cm² 

Height of the tank
= 200232 ÷ 2400
≈ 83.4 cm

Answer(s): 83.4 cm