The figure is not drawn to scale. Tank L measuring 55 cm by 42 cm by 20 cm contained 35.1 ℓ of water. Tank M measuring 40 cm by 30 cm by 35 cm contained 24 ℓ of water. Brandon poured some water from Tank L into Tank M without spilling and the water level of Tank M rose to 30 cm. What was the height of water level left in Tank L?
1 ℓ = 1000 cm³
24 ℓ = 24000 cm³
35.1 ℓ = 35.1 x 1000 = 35100 cm³

Height of water in Tank M at first
= 24000 ÷ 40 ÷ 30
= 20 cm

Increase in the height of water in Tank M
= 30 - 20
= 10 cm

Volume of water poured into Tank M
= 40 x 30 x 10
= 12000 cm³ 

Volume of water left in Tank L
= 35100 - 12000
= 23100 cm³ 

Height of water left in Tank L
= 23100 ÷ 55 ÷ 42
= 10 cm

Answer(s): 10 cm