Figure F shows a closed rectangular tank of dimensions 44 cm by 44 cm by 70 cm with a cube of edge 18 cm glued to its bottom right corner. The tank contains 90 litres of water. Figure G shows the same rectangular tank lying on its side. Find the height of the water level, in centimetres, corrected to 2 decimal places.
Height of water under the cube in Figure G 
= 44 - 18
= 26 cm

Volume of water under the cube in Figure G 
= 70 x 44 x 26
= 80080 cm³ 

1 ℓ = 1000 
90 ℓ = 90000cm³ 

Volume of water beside the cube
= 90000 - 80080
= 9920 cm³ 

Base area of water beside the cube
= (44 x 70) - (18 x 18)
= 3080 - 324
= 2756 cm² 

Height of water level beside the cube
= 9920 ÷ 2756
≈ 3.60 cm

Height of the water level
= 3.60 + 18
≈ 21.6 cm

Answer(s): 21.6 cm