The figure shows a tank made up of 3 sections. Cuboid F with a square base of side 14 cm and height 28 cm. Cube G with a side of 10 cm. Cuboid H that is 78 cm by 29 cm by 44 cm. Water from a tap above flows down at a rate of 3.7 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 62 cm from the base? Give the answer in minutes correct to nearest whole number.
Volume of G
= 10 x 10 x 10
= 1000 cm³ 

Volume of H
= 78 x 29 x 44
= 99528 cm³ 

2 ℓ = 2000 cm³ 
3.7 ℓ = 3700 cm³ 

Net increase in volume per minute
= 3700 - 2000
= 1700 cm³/min

Height of F to be filled with water
= 62 - (44 + 10)
= 8 cm

Volume of water in F
= 14 x 14 x 8
= 1568 cm³ 

Volume of water in H, G and part of F
= 99528 + 1000 + 1568
= 102096 cm³ 

Time taken to reach height
= 102096 ÷ 1700
≈ 60 min (Correct to nearest whole number)

Answer(s): 60 min