The figure, not drawn to scale, shows an empty tank measuring 30 cm by 15 cm by 20 cm. Water flows from Tap U at a rate of 500 mℓ per minute and from Tap V at a rate of 240 mℓ per minute. Tower W and Tower X have a base area of 50 cm² and 60 cm² respectively. Water is drained out of the container at a rate of 110 mℓ per minute. Find the height of the water level after 19 minutes.
Volume of the tank
= 30 x 15 x 20
= 9000 cm³ 

Volume of water flow per minute
= 500 + 240 - 110
= 630 cm³/min

Volume of water flow in 19 minutes
= 19 x 630
= 11970 cm³ 

Volume of water in the 2 towers
= 11970 - 9000
= 2970 cm³ 

Total combined base areas of 2 towers
= 50 + 60
= 110 cm² 

Height of water in 2 towers
= 2970 ÷ 110
= 27 cm

Total height of water
= 27 + 20
= 47 cm

Answer(s): 47 cm