The figure is not drawn to scale. Tank G measuring 55 cm by 41 cm by 20 cm contained 32.55 ℓ of water. Tank H measuring 40 cm by 25 cm by 32 cm contained 20 ℓ of water. Ian poured some water from Tank G into Tank H without spilling and the water level of Tank H rose to 30 cm. What was the height of water level left in Tank G?
1 ℓ = 1000 cm³
20 ℓ = 20000 cm³
32.55 ℓ = 32.55 x 1000 = 32550 cm³

Height of water in Tank H at first
= 20000 ÷ 40 ÷ 25
= 20 cm

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

Volume of water poured into Tank H
= 40 x 25 x 10
= 10000 cm³ 

Volume of water left in Tank G
= 32550 - 10000
= 22550 cm³ 

Height of water left in Tank G
= 22550 ÷ 55 ÷ 41
= 10 cm

Answer(s): 10 cm