The figure shows a container made up of 3 sections. Cuboid A with a square base of side 25 cm and height 40 cm. Cube B with a side of 15 cm. Cuboid C that is 65 cm by 26 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 container to a height of 65 cm from the base? Give the answer in minutes correct to nearest whole number.
Volume of B
= 15 x 15 x 15
= 3375 cm³ 

Volume of C
= 65 x 26 x 44
= 74360 cm³ 

2 ℓ = 2000 cm³ 
2.2 ℓ = 2200 cm³ 

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

Height of A to be filled with water
= 65 - (44 + 15)
= 6 cm

Volume of water in A
= 25 x 25 x 6
= 3750 cm³ 

Volume of water in C, B and part of A
= 74360 + 3375 + 3750
= 81485 cm³ 

Time taken to reach height
= 81485 ÷ 200
≈ 407 min (Correct to nearest whole number)

Answer(s): 407 min