The figure shows a container made up of 3 sections. Cuboid B with a square base of side 25 cm and height 23 cm. Cube C with a side of 11 cm. Cuboid D that is 80 cm by 27 cm by 43 cm. Water from a tap above flows down at a rate of 3.3 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 60 cm from the base? Give the answer in minutes correct to nearest whole number.
Volume of C
= 11 x 11 x 11
= 1331 cm³ 

Volume of D
= 80 x 27 x 43
= 92880 cm³ 

1 ℓ = 1000 cm³ 
3.3 ℓ = 3300 cm³ 

Net increase in volume per minute
= 3300 - 1000
= 2300 cm³/min

Height of B to be filled with water
= 60 - (43 + 11)
= 6 cm

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

Volume of water in D, C and part of B
= 92880 + 1331 + 3750
= 97961 cm³ 

Time taken to reach height
= 97961 ÷ 2300
≈ 43 min (Correct to nearest whole number)

Answer(s): 43 min