Pipes A and B can empty a full tank in 16 hours and 24 hours, respectively. Pipe C alone can fill the empty tank in 4 hours. If A,B and C are opened together, the tank will be 35% full after:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. hours.
Time taken by pipe A to empty the tank = 16 hours
Time taken by pipe B to empty the tank = 24 hours
Time taken by pipe C to fill the tank = 4 hours
Let the total work be (LCM of 16, 24 and 4) 48 units
Efficiency of pipe A (48/16) = -3
Efficiency of pipe B (48/24) = -2
Efficiency of pipe C (48/4) = 12
Total efficiency = (12 - 3 - 2) = 7 units
Required time taken to fill 35% of the tank = (35% of 48)/7
⇒ 12/5 hours = hours.