The figure is not drawn to scale. Tank E measuring 54 cm by 47 cm by 15 cm contained 45.78 ℓ of water. Tank F measuring 40 cm by 30 cm by 34 cm contained 18 ℓ of water. Gabriel poured some water from Tank E into Tank F without spilling and the water level of Tank F rose to 32 cm. What was the height of water level left in Tank E?
1 ℓ = 1000 cm³
18 ℓ = 18000 cm³
45.78 ℓ = 45.78 x 1000 = 45780 cm³

Height of water in Tank F at first
= 18000 ÷ 40 ÷ 30
= 15 cm

Increase in the height of water in Tank F
= 32 - 15
= 17 cm

Volume of water poured into Tank F
= 40 x 30 x 17
= 20400 cm³ 

Volume of water left in Tank E
= 45780 - 20400
= 25380 cm³ 

Height of water left in Tank E
= 25380 ÷ 54 ÷ 47
= 10 cm

Answer(s): 10 cm