The figure shows an empty rectangular tank with a capacity of 60 ℓ. The tank has a height of 25 cm. Tap Y filled the tank at a rate of 3 ℓ per minute. Tap Z drained water from the tank at a rate of 1.3 ℓ per minute. Both taps were turned on for 26 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
60 ℓ = 60 x 1000 = 60000 mℓ
Base area of the tank
=
Volumeheight =
6000025 = 2400 cm
2 (b)
Volume of water that filled the tank per minute when both taps were turned on
= 3 - 1.3
= 1.7 ℓ
Volume of water that filled the tank in 26 minutes when both taps were turned on
= 26 x 1.7
= 44.2 ℓ
Volume of water needed to fill the tank
= 60 - 44.2
= 15.8 ℓ
Answer(s): (a) 2400 cm
2; (b) 15.8 ℓ