A rectangular tank 45 cm long, 30 cm wide and 40 cm high was
56 filled with water.
- What was the volume of the water in the tank in litres?
- A tap was used to drain the water from the tank at a rate of 4 ℓ per minute. The tap was turned off when the tank was 15 filled with water. How long did it take to drain the water?
(a)
Volume of water in the tank
=
56 x 45 x 30 x 40
= 45000 cm
3 1000 mℓ = 1 ℓ
45000 mℓ = 45000 ÷ 1000 = 45 ℓ
Volume of water in the tank = 45 ℓ
(b)
Volume of water in the tank in the end
=
15 x 45 x 30 x 40
= 10800 cm
3 Volume of water that was drained from the tank
= 45000 - 10800
= 34200 cm
34 ℓ = 4 x 1000 = 4000 mℓ
Time taken for the tap to drain the water
= 34200 ÷ 4000
= 8.55 min
Answer(s): (a) 45 ℓ; (b) 8.55 min