Water flows into a container through Tap D and flows out of the container through Tap E. The capacity of a container is 72 litres. When only Tap D is turned on, the container is completely filled in 16 minutes. When only Tap E is turned on, it takes
13 hour for all the water to flow out. If both taps are turned on at the same time,
- How long does it take to fill 54% of the container?
- How much water has flowed out through Tap E by the time the container is 45 filled with water? Express your answer in litres.
(a)
Tap D :
16 min → 1 container
1 min →
116 container
13 hour =
13 x 60 = 20 min
Tap E:
20 min → 1 container
1 min →
120 container
Tap D and Tap E:
1 min →
116 -
120 =
580 -
480 =
180 container
1 container →
801 = 80 min
54% container → 54% x 80 = 43.2 min
(b)
Time taken to fill
45 of the container
1 container → 80 min
45 container → 80 x
45 = 64 min
Volume that flows out per min
=
120 container
=
120 x 72
= 3.6 ℓ
Volume of water that flowed out through Tap E in 64 min
= 64 x 3.6
= 230.4 ℓ
Answer(s): (a) 43.2 min; (b) 230.4 ℓ