The figure shows a container made up of 3 sections. Cuboid K with a square base of side 4 cm and height 45 cm. Cube L with a side of 10 cm. Cuboid M that is 70 cm by 17 cm by 44 cm. Water from a tap above flows down at a rate of 2.6 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 66 cm from the base? Give the answer in minutes correct to nearest whole number.
Volume of L
= 10 x 10 x 10
= 1000 cm³ 

Volume of M
= 70 x 17 x 44
= 52360 cm³ 

1 ℓ = 1000 cm³ 
2.6 ℓ = 2600 cm³ 

Net increase in volume per minute
= 2600 - 1000
= 1600 cm³/min

Height of K to be filled with water
= 66 - (44 + 10)
= 12 cm

Volume of water in K
= 4 x 4 x 12
= 192 cm³ 

Volume of water in M, L and part of K
= 52360 + 1000 + 192
= 53552 cm³ 

Time taken to reach height
= 53552 ÷ 1600
≈ 33 min (Correct to nearest whole number)

Answer(s): 33 min