The figure shows an empty rectangular container with a capacity of 30 ℓ. The container has a height of 20 cm. Tap C filled the container at a rate of 2.9 ℓ per minute. Tap D drained water from the container at a rate of 1.5 ℓ per minute. Both taps were turned on for 7 minutes and then turned off.
- What is the base area of the container?
- After both taps were turned off, how much more water is needed to fill the container completely? Give your answer in litres.
(a)
1 ℓ = 1000 mℓ
30 ℓ = 30 x 1000 = 30000 mℓ
Base area of the container
=
Volumeheight =
3000020 = 1500 cm
2 (b)
Volume of water that filled the container per minute when both taps were turned on
= 2.9 - 1.5
= 1.4 ℓ
Volume of water that filled the container in 7 minutes when both taps were turned on
= 7 x 1.4
= 9.8 ℓ
Volume of water needed to fill the container
= 30 - 9.8
= 20.2 ℓ
Answer(s): (a) 1500 cm
2; (b) 20.2 ℓ