Water flows into a tank through Tap X and flows out of the container through Tap Y. The capacity of a tank is 68 litres. When only Tap X is turned on, the container is completely filled in 12 minutes. When only Tap Y 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 84% of the tank?
- How much water has flowed out through Tap Y by the time the tank is 45 filled with water? Express your answer in litres.
(a)
Tap X :
12 min → 1 tank
1 min →
112 tank
13 hour =
13 x 60 = 20 min
Tap Y:
20 min → 1 tank
1 min →
120 tank
Tap X and Tap Y:
1 min →
112 -
120 =
560 -
360 =
130 tank
1 tank →
301 = 30 min
84% tank → 84% x 30 = 25.2 min
(b)
Time taken to fill
45 of the tank
1 tank → 30 min
45 tank → 30 x
45 = 24 min
Volume that flows out per min
=
120 tank
=
120 x 68
= 3.4 ℓ
Volume of water that flowed out through Tap Y in 24 min
= 24 x 3.4
= 81.6 ℓ
Answer(s): (a) 25.2 min; (b) 81.6 ℓ