The figure is not drawn to scale. Tank X measuring 51 cm by 45 cm by 15 cm contained 33.37 ℓ of water. Tank Y measuring 40 cm by 35 cm by 35 cm contained 21 ℓ of water. Albert poured some water from Tank X into Tank Y without spilling and the water level of Tank Y rose to 29 cm. What was the height of water level left in Tank X?
1 ℓ = 1000 cm³
21 ℓ = 21000 cm³
33.37 ℓ = 33.37 x 1000 = 33370 cm³

Height of water in Tank Y at first
= 21000 ÷ 40 ÷ 35
= 15 cm

Increase in the height of water in Tank Y
= 29 - 15
= 14 cm

Volume of water poured into Tank Y
= 40 x 35 x 14
= 19600 cm³ 

Volume of water left in Tank X
= 33370 - 19600
= 13770 cm³ 

Height of water left in Tank X
= 13770 ÷ 51 ÷ 45
= 6 cm

Answer(s): 6 cm