The figure is not drawn to scale. Tank E measuring 50 cm by 47 cm by 12 cm contained 25.4 ℓ of water. Tank F measuring 40 cm by 25 cm by 32 cm contained 12 ℓ of water. Archie poured some water from Tank E into Tank F without spilling and the water level of Tank F rose to 28 cm. What was the height of water level left in Tank E?
1 ℓ = 1000 cm³
12 ℓ = 12000 cm³
25.4 ℓ = 25.4 x 1000 = 25400 cm³

Height of water in Tank F at first
= 12000 ÷ 40 ÷ 25
= 12 cm

Increase in the height of water in Tank F
= 28 - 12
= 16 cm

Volume of water poured into Tank F
= 40 x 25 x 16
= 16000 cm³ 

Volume of water left in Tank E
= 25400 - 16000
= 9400 cm³ 

Height of water left in Tank E
= 9400 ÷ 50 ÷ 47
= 4 cm

Answer(s): 4 cm