The figure shows a container made up of 3 sections. Cuboid G with a square base of side 25 cm and height 45 cm. Cube H with a side of 11 cm. Cuboid J that is 69 cm by 14 cm by 44 cm. Water from a tap above flows down at a rate of 2.7 litres per minute while water is drained out from the bottom at a rate of 1 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 H
= 11 x 11 x 11
= 1331 cm³ 

Volume of J
= 69 x 14 x 44
= 42504 cm³ 

1 ℓ = 1000 cm³ 
2.7 ℓ = 2700 cm³ 

Net increase in volume per minute
= 2700 - 1000
= 1700 cm³/min

Height of G to be filled with water
= 69 - (44 + 11)
= 14 cm

Volume of water in G
= 25 x 25 x 14
= 8750 cm³ 

Volume of water in J, H and part of G
= 42504 + 1331 + 8750
= 52585 cm³ 

Time taken to reach height
= 52585 ÷ 1700
≈ 31 min (Correct to nearest whole number)

Answer(s): 31 min