The figure is not drawn to scale. Tank H measuring 51 cm by 46 cm by 20 cm contained 23.73 ℓ of water. Tank J measuring 40 cm by 30 cm by 36 cm contained 24 ℓ of water. Charlie poured some water from Tank H into Tank J without spilling and the water level of Tank J rose to 30 cm. What was the height of water level left in Tank H?
1 ℓ = 1000 cm³
24 ℓ = 24000 cm³
23.73 ℓ = 23.73 x 1000 = 23730 cm³

Height of water in Tank J at first
= 24000 ÷ 40 ÷ 30
= 20 cm

Increase in the height of water in Tank J
= 30 - 20
= 10 cm

Volume of water poured into Tank J
= 40 x 30 x 10
= 12000 cm³ 

Volume of water left in Tank H
= 23730 - 12000
= 11730 cm³ 

Height of water left in Tank H
= 11730 ÷ 51 ÷ 46
= 5 cm

Answer(s): 5 cm