A rectangular tank 40 cm long, 20 cm wide and 21 cm high was
35 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 17 filled with water. How long did it take to drain the water?
(a)
Volume of water in the tank
=
35 x 40 x 20 x 21
= 10080 cm
3 1000 mℓ = 1 ℓ
10080 mℓ = 10080 ÷ 1000 = 10.08 ℓ
Volume of water in the tank = 10.08 ℓ
(b)
Volume of water in the tank in the end
=
17 x 40 x 20 x 21
= 2400 cm
3 Volume of water that was drained from the tank
= 10080 - 2400
= 7680 cm
34 ℓ = 4 x 1000 = 4000 mℓ
Time taken for the tap to drain the water
= 7680 ÷ 4000
= 1.92 min
Answer(s): (a) 10.08 ℓ; (b) 1.92 min