The figure is not drawn to scale. Tank S measuring 54 cm by 44 cm by 15 cm contained 42.96 ℓ of water. Tank T measuring 40 cm by 30 cm by 34 cm contained 18 ℓ of water. Charlie poured some water from Tank S into Tank T without spilling and the water level of Tank T rose to 31 cm. What was the height of water level left in Tank S?
1 ℓ = 1000 cm³
18 ℓ = 18000 cm³
42.96 ℓ = 42.96 x 1000 = 42960 cm³

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

Increase in the height of water in Tank T
= 31 - 15
= 16 cm

Volume of water poured into Tank T
= 40 x 30 x 16
= 19200 cm³ 

Volume of water left in Tank S
= 42960 - 19200
= 23760 cm³ 

Height of water left in Tank S
= 23760 ÷ 54 ÷ 44
= 10 cm

Answer(s): 10 cm