Water flows into a tank through Tap C and flows out of the container through Tap D. The capacity of a tank is 46 litres. When only Tap C is turned on, the container is completely filled in 12 minutes. When only Tap D 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 32% of the tank?
- How much water has flowed out through Tap D by the time the tank is 35 filled with water? Express your answer in litres.
(a)
Tap C :
12 min → 1 tank
1 min →
112 tank
13 hour =
13 x 60 = 20 min
Tap D:
20 min → 1 tank
1 min →
120 tank
Tap C and Tap D:
1 min →
112 -
120 =
560 -
360 =
130 tank
1 tank →
301 = 30 min
32% tank → 32% x 30 = 9.6 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 46
= 2.3 ℓ
Volume of water that flowed out through Tap D in 18 min
= 18 x 2.3
= 41.4 ℓ
Answer(s): (a) 9.6 min; (b) 41.4 ℓ