The figure is not drawn to scale. Tank E measuring 50 cm by 43 cm by 13 cm contained 25.9 ℓ of water. Tank F measuring 40 cm by 25 cm by 35 cm contained 13 ℓ of water. Ahmad poured some water from Tank E into Tank F without spilling and the water level of Tank F rose to 26 cm. What was the height of water level left in Tank E?
1 ℓ = 1000 cm³
13 ℓ = 13000 cm³
25.9 ℓ = 25.9 x 1000 = 25900 cm³

Height of water in Tank F at first
= 13000 ÷ 40 ÷ 25
= 13 cm

Increase in the height of water in Tank F
= 26 - 13
= 13 cm

Volume of water poured into Tank F
= 40 x 25 x 13
= 13000 cm³ 

Volume of water left in Tank E
= 25900 - 13000
= 12900 cm³ 

Height of water left in Tank E
= 12900 ÷ 50 ÷ 43
= 6 cm

Answer(s): 6 cm