A) 10 min. 20 sec. | B) 11 min. 45 sec. |

C) 12 min. 30 sec. | D) 14 min. 40 sec. |

Explanation:

Part filled in 4 minutes =

Remaining part =

Part filled by B in 1 minute =

The tank will be full in (4 min. + 10 min. + 40 sec.) = 14 min. 40 sec

A) 24.315 minutes | B) 26.166 minutes |

C) 22.154 minutes | D) 24 minutes |

Explanation:

Upto first 5 minutes I, J and K will fill => 5[(1/20)+(1/30)+(1/40)] = 65/120

For next 6 minutes, J and K will fill => 6[(1/30)+(1/40)] = 42/120

So tank filled upto first 11 minutes = (65/120) + (42/120) = 107/120

So remaining tank = 13/120

Now at the moment filling with C and leakage @ 1/60 per minute= (1/40) - (1/70) = 3/280

So time taken to fill remaining 13/120 tank =(13/120) /(3/280) = 91/6 minutes

Hence total time taken to completely fill the tank = 5 + 6 + 91/6 = 26.16 minutes.

A) 3 minutes | B) 2 minutes |

C) 4 minutes | D) 5 minutes |

Explanation:

Let the total capacity of tank be 90 liters.

Capacity of tank filled in 1 minute by K = 3 liters.

Capacity of tank filled in 1 minute by L = 15 liters.

Therefore, capacity of the tank filled by both K and L in 1 minute = 18 liters.

Hence, time taken by both the pipes to overflow the tank = 90/18 = 5 minutes.

A) 48min | B) 72min |

C) 24min | D) None of these |

Explanation:

Given taps X and Y can fill the tank in 30 and 40 minutes respectively. Therefore,

part filled by tap X in 1 minute = 1/30

part filled by tap Y in 1 minute = 1/40

Tap Z can empty the tank in 60 minutes. Therefore,

part emptied by tap Z in 1 minute = 1/60

Net part filled by Pipes X,Y,Z together in 1 minute =

= 5/120 = 1/24

i.e., the tank can be filled in 24 minutes.

A) 49.5 min | B) 50 min |

C) 51 min | D) 52 min |

Explanation:

The work to be done = Capacity of reservoir = 30 litres.

1^{st} Minute inlet pipe opened 5 lit filled

2^{nd} minute inlet pipe closed; outlet pipe opened 4 lit emptied

In 2 minutes (5 litres - 4 litres = 1lit) is filled into the reservoir.

It takes 2 minutes to fill 1lit it takes 50 minutes to fill 25 litres into the reservoir.

In the 51^{st} minute inlet pipe is opened and the reservoir is filled.

A) 50 m^3/min | B) 60 m^3/min |

C) 72 m^3/min | D) None of these |

Explanation:

Let the filling capacity of the pump be x /min.

Then, emptying capacity of the pump=(x+10) /min.

so,