The figure is not drawn to scale. Tank R measuring 54 cm by 45 cm by 15 cm contained 36.24 ℓ of water. Tank S measuring 40 cm by 30 cm by 35 cm contained 18 ℓ of water. Daniel poured some water from Tank R into Tank S without spilling and the water level of Tank S rose to 29 cm. What was the height of water level left in Tank R?
1 ℓ = 1000 cm³
18 ℓ = 18000 cm³
36.24 ℓ = 36.24 x 1000 = 36240 cm³

Height of water in Tank S at first
= 18000 ÷ 40 ÷ 30
= 15 cm

Increase in the height of water in Tank S
= 29 - 15
= 14 cm

Volume of water poured into Tank S
= 40 x 30 x 14
= 16800 cm³ 

Volume of water left in Tank R
= 36240 - 16800
= 19440 cm³ 

Height of water left in Tank R
= 19440 ÷ 54 ÷ 45
= 8 cm

Answer(s): 8 cm