Water flows into a container through Tap U and flows out of the container through Tap V. The capacity of a container is 42 litres. When only Tap U is turned on, the container is completely filled in 12 minutes. When only Tap V is turned on, it takes
14 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 38% of the container?
- How much water has flowed out through Tap V by the time the container is 45 filled with water? Express your answer in litres.
(a)
Tap U :
12 min → 1 container
1 min →
112 container
14 hour =
14 x 60 = 15 min
Tap V:
15 min → 1 container
1 min →
115 container
Tap U and Tap V:
1 min →
112 -
115 =
560 -
460 =
160 container
1 container →
601 = 60 min
38% container → 38% x 60 = 22.8 min
(b)
Time taken to fill
45 of the container
1 container → 60 min
45 container → 60 x
45 = 48 min
Volume that flows out per min
=
115 container
=
115 x 42
= 2.8 ℓ
Volume of water that flowed out through Tap V in 48 min
= 48 x 2.8
= 134.4 ℓ
Answer(s): (a) 22.8 min; (b) 134.4 ℓ