The figure shows a container made up of 3 sections. Cuboid D with a square base of side 9 cm and height 36 cm. Cube E with a side of 12 cm. Cuboid F that is 80 cm by 28 cm by 46 cm. Water from a tap above flows down at a rate of 2.5 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 E
= 12 x 12 x 12
= 1728 cm³ 

Volume of F
= 80 x 28 x 46
= 103040 cm³ 

2 ℓ = 2000 cm³ 
2.5 ℓ = 2500 cm³ 

Net increase in volume per minute
= 2500 - 2000
= 500 cm³/min

Height of D to be filled with water
= 69 - (46 + 12)
= 11 cm

Volume of water in D
= 9 x 9 x 11
= 891 cm³ 

Volume of water in F, E and part of D
= 103040 + 1728 + 891
= 105659 cm³ 

Time taken to reach height
= 105659 ÷ 500
≈ 211 min (Correct to nearest whole number)

Answer(s): 211 min