9 identical 7-cm cubes are placed in an empty rectangular tank of length 75 cm and width 25 cm. The tank is then filled with water from a tap flowing at a rate of 6 litres per minute. It takes 11 minutes to fill up ¹₃ 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 9 cubes
= 9 x 343
= 3087 cm³ 

1 ℓ = 1000 mℓ
6 ℓ = 6000 mℓ

Volume of water in the tank
= 11 x 6000
= 66000 mℓ

Volume of ¹₃ of the tank
= 66000 + 3087
= 69087 mℓ

Volume of the tank
= 69087 ÷ ¹₃
= 69087 x ³₁
= 207261 mℓ

Base area
= 75 x 25
= 1875 cm² 

Height of the tank
= 207261 ÷ 1875
≈ 110.5 cm

Answer(s): 110.5 cm