Figure Q shows a closed rectangular tank of dimensions 46 cm by 46 cm by 70 cm with a cube of edge 26 cm glued to its bottom right corner. The tank contains 70 litres of water. Figure R 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 R 
= 46 - 26
= 20 cm

Volume of water under the cube in Figure R 
= 70 x 46 x 20
= 64400 cm³ 

1 ℓ = 1000 
70 ℓ = 70000cm³ 

Volume of water beside the cube
= 70000 - 64400
= 5600 cm³ 

Base area of water beside the cube
= (46 x 70) - (26 x 26)
= 3220 - 676
= 2544 cm² 

Height of water level beside the cube
= 5600 ÷ 2544
≈ 2.20 cm

Height of the water level
= 2.20 + 26
≈ 28.2 cm

Answer(s): 28.2 cm