The figure shows an empty rectangular tank with a capacity of 65 ℓ. The tank has a height of 26 cm. Tap J filled the tank at a rate of 2.6 ℓ per minute. Tap K drained water from the tank at a rate of 1.4 ℓ per minute. Both taps were turned on for 12 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
65 ℓ = 65 x 1000 = 65000 mℓ
Base area of the tank
=
Volumeheight =
6500026 = 2500 cm
2 (b)
Volume of water that filled the tank per minute when both taps were turned on
= 2.6 - 1.4
= 1.2 ℓ
Volume of water that filled the tank in 12 minutes when both taps were turned on
= 12 x 1.2
= 14.4 ℓ
Volume of water needed to fill the tank
= 65 - 14.4
= 50.6 ℓ
Answer(s): (a) 2500 cm
2; (b) 50.6 ℓ