The figure shows a tank made up of 3 sections. Cuboid E with a square base of side 9 cm and height 42 cm. Cube F with a side of 18 cm. Cuboid G that is 72 cm by 29 cm by 43 cm. Water from a tap above flows down at a rate of 3.9 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 69 cm from the base? Give the answer in minutes correct to nearest whole number.

3 m

(3 m)

(3 m)