The figure shows an empty rectangular container with a capacity of 69 ℓ. The container has a height of 30 cm. Tap B filled the container at a rate of 2.5 ℓ per minute. Tap C drained water from the container at a rate of 1.4 ℓ per minute. Both taps were turned on for 18 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
69 ℓ = 69 x 1000 = 69000 mℓ
Base area of the container
=
Volumeheight =
6900030 = 2300 cm
2 (b)
Volume of water that filled the container per minute when both taps were turned on
= 2.5 - 1.4
= 1.1 ℓ
Volume of water that filled the container in 18 minutes when both taps were turned on
= 18 x 1.1
= 19.8 ℓ
Volume of water needed to fill the container
= 69 - 19.8
= 49.2 ℓ
Answer(s): (a) 2300 cm
2; (b) 49.2 ℓ