The figure is not drawn to scale. Tank Y measuring 52 cm by 43 cm by 25 cm contained 28.36 ℓ of water. Tank Z measuring 40 cm by 25 cm by 34 cm contained 25 ℓ of water. Zeph poured some water from Tank Y into Tank Z without spilling and the water level of Tank Z rose to 31 cm. What was the height of water level left in Tank Y?
1 ℓ = 1000 cm³
25 ℓ = 25000 cm³
28.36 ℓ = 28.36 x 1000 = 28360 cm³

Height of water in Tank Z at first
= 25000 ÷ 40 ÷ 25
= 25 cm

Increase in the height of water in Tank Z
= 31 - 25
= 6 cm

Volume of water poured into Tank Z
= 40 x 25 x 6
= 6000 cm³ 

Volume of water left in Tank Y
= 28360 - 6000
= 22360 cm³ 

Height of water left in Tank Y
= 22360 ÷ 52 ÷ 43
= 10 cm

Answer(s): 10 cm