Water flows into a tank through Tap T and flows out of the container through Tap U. The capacity of a tank is 54 litres. When only Tap T is turned on, the container is completely filled in 12 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 68% of the tank?
- How much water has flowed out through Tap U by the time the tank is 35 filled with water? Express your answer in litres.
(a)
Tap T :
12 min → 1 tank
1 min →
112 tank
13 hour =
13 x 60 = 20 min
Tap U:
20 min → 1 tank
1 min →
120 tank
Tap T and Tap U:
1 min →
112 -
120 =
560 -
360 =
130 tank
1 tank →
301 = 30 min
68% tank → 68% x 30 = 20.4 min
(b)
Time taken to fill
35 of the tank
1 tank → 30 min
35 tank → 30 x
35 = 18 min
Volume that flows out per min
=
120 tank
=
120 x 54
= 2.7 ℓ
Volume of water that flowed out through Tap U in 18 min
= 18 x 2.7
= 48.6 ℓ
Answer(s): (a) 20.4 min; (b) 48.6 ℓ