A rectangular tank measuring 75 cm by 70 cm by 30 cm was ¹₅ filled with water. Nora turned on a tap at 10.30 p.m. to fill more water into the tank. She turned off the tap at 10.45 p.m. The tank was ⁶₇ 
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
= ¹₅ x 75 x 70 x 30
= 31500 cm³

Volume of water in the tank in the end
= ⁶₇ x 75 x 70 x 30
= 135000 cm³

Volume of water added into the tank by the tap
= 135000 - 31500
= 103500 cm³

1000 mℓ = 1 ℓ
103500 mℓ = 103500 ÷ 1000 = 103.5 ℓ

From 10.30 p.m. to 10.45 p.m.: 15 min

Volume of water that flowed out of the tap in a minute
= 103.5 ÷ 15
= 6.9 ℓ 

Answer(s): 6.9 ℓ