The figure shows a container made up of 3 sections. Cuboid T with a square base of side 25 cm and height 46 cm. Cube U with a side of 11 cm. Cuboid V that is 71 cm by 14 cm by 46 cm. Water from a tap above flows down at a rate of 2.3 litres per minute while water is drained out from the bottom at a rate of 2 litre per minute. How long did it take to fill up the container to a height of 70 cm from the base? Give the answer in minutes correct to nearest whole number.
Volume of U
= 11 x 11 x 11
= 1331 cm³ 

Volume of V
= 71 x 14 x 46
= 45724 cm³ 

2 ℓ = 2000 cm³ 
2.3 ℓ = 2300 cm³ 

Net increase in volume per minute
= 2300 - 2000
= 300 cm³/min

Height of T to be filled with water
= 70 - (46 + 11)
= 13 cm

Volume of water in T
= 25 x 25 x 13
= 8125 cm³ 

Volume of water in V, U and part of T
= 45724 + 1331 + 8125
= 55180 cm³ 

Time taken to reach height
= 55180 ÷ 300
≈ 184 min (Correct to nearest whole number)

Answer(s): 184 min