The figure shows an empty rectangular container with a capacity of 81 ℓ. The container has a height of 30 cm. Tap D filled the container at a rate of 3.4 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 15 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
81 ℓ = 81 x 1000 = 81000 mℓ
Base area of the container
=
Volumeheight =
8100030 = 2700 cm
2 (b)
Volume of water that filled the container per minute when both taps were turned on
= 3.4 - 1.9
= 1.5 ℓ
Volume of water that filled the container in 15 minutes when both taps were turned on
= 15 x 1.5
= 22.5 ℓ
Volume of water needed to fill the container
= 81 - 22.5
= 58.5 ℓ
Answer(s): (a) 2700 cm
2; (b) 58.5 ℓ