The figure is not drawn to scale. Tank E measuring 50 cm by 46 cm by 25 cm contained 17.9 ℓ of water. Tank F measuring 40 cm by 32 cm by 36 cm contained 32 ℓ of water. Carl poured some water from Tank E into Tank F without spilling and the water level of Tank F rose to 30 cm. What was the height of water level left in Tank E?
1 ℓ = 1000 cm³
32 ℓ = 32000 cm³
17.9 ℓ = 17.9 x 1000 = 17900 cm³

Height of water in Tank F at first
= 32000 ÷ 40 ÷ 32
= 25 cm

Increase in the height of water in Tank F
= 30 - 25
= 5 cm

Volume of water poured into Tank F
= 40 x 32 x 5
= 6400 cm³ 

Volume of water left in Tank E
= 17900 - 6400
= 11500 cm³ 

Height of water left in Tank E
= 11500 ÷ 50 ÷ 46
= 5 cm

Answer(s): 5 cm