The figure shows a container made up of 3 sections. Cuboid T with a square base of side 14 cm and height 46 cm. Cube U with a side of 15 cm. Cuboid V that is 62 cm by 20 cm by 40 cm. Water from a tap above flows down at a rate of 2.6 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 69 cm from the base? Give the answer in minutes correct to nearest whole number.
Volume of U
= 15 x 15 x 15
= 3375 cm³ 

Volume of V
= 62 x 20 x 40
= 49600 cm³ 

2 ℓ = 2000 cm³ 
2.6 ℓ = 2600 cm³ 

Net increase in volume per minute
= 2600 - 2000
= 600 cm³/min

Height of T to be filled with water
= 69 - (40 + 15)
= 14 cm

Volume of water in T
= 14 x 14 x 14
= 2744 cm³ 

Volume of water in V, U and part of T
= 49600 + 3375 + 2744
= 55719 cm³ 

Time taken to reach height
= 55719 ÷ 600
≈ 93 min (Correct to nearest whole number)

Answer(s): 93 min