The figure is not drawn to scale. Tank N measuring 55 cm by 46 cm by 20 cm contained 22.65 ℓ of water. Tank P measuring 40 cm by 25 cm by 36 cm contained 20 ℓ of water. Japheth poured some water from Tank N into Tank P without spilling and the water level of Tank P rose to 30 cm. What was the height of water level left in Tank N?
1 ℓ = 1000 cm³
20 ℓ = 20000 cm³
22.65 ℓ = 22.65 x 1000 = 22650 cm³

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

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

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

Volume of water left in Tank N
= 22650 - 10000
= 12650 cm³ 

Height of water left in Tank N
= 12650 ÷ 55 ÷ 46
= 5 cm

Answer(s): 5 cm