The figure shows a container made up of 3 sections. Cuboid L with a square base of side 14 cm and height 27 cm. Cube M with a side of 11 cm. Cuboid N that is 69 cm by 17 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 container to a height of 65 cm from the base? Give the answer in minutes correct to nearest whole number.
Volume of M
= 11 x 11 x 11
= 1331 cm³ 

Volume of N
= 69 x 17 x 44
= 51612 cm³ 

2 ℓ = 2000 cm³ 
2.4 ℓ = 2400 cm³ 

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

Height of L to be filled with water
= 65 - (44 + 11)
= 10 cm

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

Volume of water in N, M and part of L
= 51612 + 1331 + 1960
= 54903 cm³ 

Time taken to reach height
= 54903 ÷ 400
≈ 137 min (Correct to nearest whole number)

Answer(s): 137 min