The figure is not drawn to scale. Tank B measuring 53 cm by 45 cm by 25 cm contained 9.97 ℓ of water. Tank C measuring 40 cm by 26 cm by 34 cm contained 26 ℓ of water. Harry poured some water from Tank B into Tank C without spilling and the water level of Tank C rose to 30 cm. What was the height of water level left in Tank B?
1 ℓ = 1000 cm³
26 ℓ = 26000 cm³
9.97 ℓ = 9.97 x 1000 = 9970 cm³

Height of water in Tank C at first
= 26000 ÷ 40 ÷ 26
= 25 cm

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

Volume of water poured into Tank C
= 40 x 26 x 5
= 5200 cm³ 

Volume of water left in Tank B
= 9970 - 5200
= 4770 cm³ 

Height of water left in Tank B
= 4770 ÷ 53 ÷ 45
= 2 cm

Answer(s): 2 cm