The figure shows an empty rectangular container with a capacity of 42 ℓ. The container has a height of 30 cm. Tap D filled the container at a rate of 3.1 ℓ per minute. Tap E drained water from the container at a rate of 1.9 ℓ per minute. Both taps were turned on for 28 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
42 ℓ = 42 x 1000 = 42000 mℓ
Base area of the container
=
Volumeheight =
4200030 = 1400 cm
2 (b)
Volume of water that filled the container per minute when both taps were turned on
= 3.1 - 1.9
= 1.2 ℓ
Volume of water that filled the container in 28 minutes when both taps were turned on
= 28 x 1.2
= 33.6 ℓ
Volume of water needed to fill the container
= 42 - 33.6
= 8.4 ℓ
Answer(s): (a) 1400 cm
2; (b) 8.4 ℓ