Water flows into a container through Tap T and flows out of the container through Tap U. The capacity of a container is 48 litres. When only Tap T is turned on, the container is completely filled in 16 minutes. When only Tap U 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 64% of the container?
- How much water has flowed out through Tap U by the time the container is 25 filled with water? Express your answer in litres.
(a)
Tap T :
16 min → 1 container
1 min →
116 container
13 hour =
13 x 60 = 20 min
Tap U:
20 min → 1 container
1 min →
120 container
Tap T and Tap U:
1 min →
116 -
120 =
580 -
480 =
180 container
1 container →
801 = 80 min
64% container → 64% x 80 = 51.2 min
(b)
Time taken to fill
25 of the container
1 container → 80 min
25 container → 80 x
25 = 32 min
Volume that flows out per min
=
120 container
=
120 x 48
= 2.4 ℓ
Volume of water that flowed out through Tap U in 32 min
= 32 x 2.4
= 76.8 ℓ
Answer(s): (a) 51.2 min; (b) 76.8 ℓ