The figure shows a tank made up of 3 sections. Cuboid H with a square base of side 4 cm and height 28 cm. Cube J with a side of 14 cm. Cuboid K that is 62 cm by 13 cm by 44 cm. Water from a tap above flows down at a rate of 2.2 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 tank to a height of 67 cm from the base? Give the answer in minutes correct to nearest whole number.
Volume of J
= 14 x 14 x 14
= 2744 cm³ 

Volume of K
= 62 x 13 x 44
= 35464 cm³ 

2 ℓ = 2000 cm³ 
2.2 ℓ = 2200 cm³ 

Net increase in volume per minute
= 2200 - 2000
= 200 cm³/min

Height of H to be filled with water
= 67 - (44 + 14)
= 9 cm

Volume of water in H
= 4 x 4 x 9
= 144 cm³ 

Volume of water in K, J and part of H
= 35464 + 2744 + 144
= 38352 cm³ 

Time taken to reach height
= 38352 ÷ 200
≈ 192 min (Correct to nearest whole number)

Answer(s): 192 min