Water flows into a container through Tap M and flows out of the container through Tap N. The capacity of a container is 60 litres. When only Tap M is turned on, the container is completely filled in 14 minutes. When only Tap N 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 82% of the container?
- How much water has flowed out through Tap N by the time the container is 25 filled with water? Express your answer in litres.
(a)
Tap M :
14 min → 1 container
1 min →
114 container
14 hour =
14 x 60 = 15 min
Tap N:
15 min → 1 container
1 min →
115 container
Tap M and Tap N:
1 min →
114 -
115 =
15210 -
14210 =
1210 container
1 container →
2101 = 210 min
82% container → 82% x 210 = 172.2 min
(b)
Time taken to fill
25 of the container
1 container → 210 min
25 container → 210 x
25 = 84 min
Volume that flows out per min
=
115 container
=
115 x 60
= 4 ℓ
Volume of water that flowed out through Tap N in 84 min
= 84 x 4
= 336 ℓ
Answer(s): (a) 172.2 min; (b) 336 ℓ