Water flows into a container through Tap S and flows out of the container through Tap T. The capacity of a container is 46 litres. When only Tap S is turned on, the container is completely filled in 12 minutes. When only Tap T 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 30% of the container?
- How much water has flowed out through Tap T by the time the container is 25 filled with water? Express your answer in litres.
(a)
Tap S :
12 min → 1 container
1 min →
112 container
13 hour =
13 x 60 = 20 min
Tap T:
20 min → 1 container
1 min →
120 container
Tap S and Tap T:
1 min →
112 -
120 =
560 -
360 =
130 container
1 container →
301 = 30 min
30% container → 30% x 30 = 9 min
(b)
Time taken to fill
25 of the container
1 container → 30 min
25 container → 30 x
25 = 12 min
Volume that flows out per min
=
120 container
=
120 x 46
= 2.3 ℓ
Volume of water that flowed out through Tap T in 12 min
= 12 x 2.3
= 27.6 ℓ
Answer(s): (a) 9 min; (b) 27.6 ℓ