The figure is not drawn to scale. Tank Y measuring 54 cm by 47 cm by 24 cm contained 17.19 ℓ of water. Tank Z measuring 45 cm by 25 cm by 36 cm contained 27 ℓ of water. Peter poured some water from Tank Y into Tank Z without spilling and the water level of Tank Z rose to 28 cm. What was the height of water level left in Tank Y?
1 ℓ = 1000 cm³
27 ℓ = 27000 cm³
17.19 ℓ = 17.19 x 1000 = 17190 cm³

Height of water in Tank Z at first
= 27000 ÷ 45 ÷ 25
= 24 cm

Increase in the height of water in Tank Z
= 28 - 24
= 4 cm

Volume of water poured into Tank Z
= 45 x 25 x 4
= 4500 cm³ 

Volume of water left in Tank Y
= 17190 - 4500
= 12690 cm³ 

Height of water left in Tank Y
= 12690 ÷ 54 ÷ 47
= 5 cm

Answer(s): 5 cm