A rectangular tank measuring 80 cm by 70 cm by 28 cm was ¹₈ filled with water. Nicole turned on a tap at 5.11 p.m. to fill more water into the tank. She turned off the tap at 5.31 p.m. The tank was ⁴₇ 
filled with water. Given that the water flowed out of the tap at the same rate, find the volume of water that flowed out of the tap in a minute. Give your answer in litres.
Volume of water in the tank at first
= ¹₈ x 80 x 70 x 28
= 19600 cm³

Volume of water in the tank in the end
= ⁴₇ x 80 x 70 x 28
= 89600 cm³

Volume of water added into the tank by the tap
= 89600 - 19600
= 70000 cm³

1000 mℓ = 1 ℓ
70000 mℓ = 70000 ÷ 1000 = 70 ℓ

From 5.11 p.m. to 5.31 p.m.: 20 min

Volume of water that flowed out of the tap in a minute
= 70 ÷ 20
= 3.5 ℓ 

Answer(s): 3.5 ℓ