The figure shows a tank made up of 3 sections. Cuboid Z with a square base of side 14 cm and height 32 cm. Cube A with a side of 13 cm. Cuboid B that is 68 cm by 26 cm by 44 cm. Water from a tap above flows down at a rate of 2.4 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 A
= 13 x 13 x 13
= 2197 cm³ 

Volume of B
= 68 x 26 x 44
= 77792 cm³ 

2 ℓ = 2000 cm³ 
2.4 ℓ = 2400 cm³ 

Net increase in volume per minute
= 2400 - 2000
= 400 cm³/min

Height of Z to be filled with water
= 67 - (44 + 13)
= 10 cm

Volume of water in Z
= 14 x 14 x 10
= 1960 cm³ 

Volume of water in B, A and part of Z
= 77792 + 2197 + 1960
= 81949 cm³ 

Time taken to reach height
= 81949 ÷ 400
≈ 205 min (Correct to nearest whole number)

Answer(s): 205 min