The figure shows an empty rectangular tank with a capacity of 50 ℓ. The tank has a height of 20 cm. Tap B filled the tank at a rate of 2.6 ℓ per minute. Tap C drained water from the tank at a rate of 1.5 ℓ per minute. Both taps were turned on for 6 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
50 ℓ = 50 x 1000 = 50000 mℓ
Base area of the tank
=
Volumeheight =
5000020 = 2500 cm
2 (b)
Volume of water that filled the tank per minute when both taps were turned on
= 2.6 - 1.5
= 1.1 ℓ
Volume of water that filled the tank in 6 minutes when both taps were turned on
= 6 x 1.1
= 6.6 ℓ
Volume of water needed to fill the tank
= 50 - 6.6
= 43.4 ℓ
Answer(s): (a) 2500 cm
2; (b) 43.4 ℓ