Water flows into a tank through Tap E and flows out of the container through Tap F. The capacity of a tank is 70 litres. When only Tap E is turned on, the container is completely filled in 16 minutes. When only Tap F 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 48% of the tank?
- How much water has flowed out through Tap F by the time the tank is 25 filled with water? Express your answer in litres.
(a)
Tap E :
16 min → 1 tank
1 min →
116 tank
13 hour =
13 x 60 = 20 min
Tap F:
20 min → 1 tank
1 min →
120 tank
Tap E and Tap F:
1 min →
116 -
120 =
580 -
480 =
180 tank
1 tank →
801 = 80 min
48% tank → 48% x 80 = 38.4 min
(b)
Time taken to fill
25 of the tank
1 tank → 80 min
25 tank → 80 x
25 = 32 min
Volume that flows out per min
=
120 tank
=
120 x 70
= 3.5 ℓ
Volume of water that flowed out through Tap F in 32 min
= 32 x 3.5
= 112 ℓ
Answer(s): (a) 38.4 min; (b) 112 ℓ