The figure shows an empty rectangular tank with a capacity of 66 ℓ. The tank has a height of 22 cm. Tap F filled the tank at a rate of 3.2 ℓ per minute. Tap G drained water from the tank at a rate of 1.3 ℓ per minute. Both taps were turned on for 9 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
66 ℓ = 66 x 1000 = 66000 mℓ
Base area of the tank
=
Volumeheight =
6600022 = 3000 cm
2 (b)
Volume of water that filled the tank per minute when both taps were turned on
= 3.2 - 1.3
= 1.9 ℓ
Volume of water that filled the tank in 9 minutes when both taps were turned on
= 9 x 1.9
= 17.1 ℓ
Volume of water needed to fill the tank
= 66 - 17.1
= 48.9 ℓ
Answer(s): (a) 3000 cm
2; (b) 48.9 ℓ