The figure shows an empty rectangular tank with a capacity of 56 ℓ. The tank has a height of 20 cm. Tap V filled the tank at a rate of 3.3 ℓ per minute. Tap W drained water from the tank at a rate of 1.8 ℓ per minute. Both taps were turned on for 26 minutes and then turned off.
- What is the base area of the tank?
- After both taps were turned off, how much more water is needed to fill the tank completely? Give your answer in litres.
(a)
1 ℓ = 1000 mℓ
56 ℓ = 56 x 1000 = 56000 mℓ
Base area of the tank
=
Volumeheight =
5600020 = 2800 cm
2 (b)
Volume of water that filled the tank per minute when both taps were turned on
= 3.3 - 1.8
= 1.5 ℓ
Volume of water that filled the tank in 26 minutes when both taps were turned on
= 26 x 1.5
= 39 ℓ
Volume of water needed to fill the tank
= 56 - 39
= 17 ℓ
Answer(s): (a) 2800 cm
2; (b) 17 ℓ