A) 81 min | B) 108 min |

C) 144 min | D) 192 min |

Explanation:

Let the slower pipe alone fill the tank in x minutes.

Then,faster pipe will fill it in x/3 minutes.

A) 70 lit | B) 170 lit |

C) 90 lit | D) 190 lit |

Explanation:

Given A alone can fill the tank of capacity 240 lit in 16 hrs.

=> A can fill in 1 hr = 240/16 = 15 lit

=> B alone can fill the tank of capacity 240 lit in 12 hrs.

=> B can fill in 1 hr = 240/12 = 20 lit

Now, (A + B) in 1 hr = 15 + 20 = 35 lit

But they are opened for 2 hrs

=> 2 x 35 = 70 lit rae filled

Remaining water to be filled in tank of 240 lit = 240 - 70 = 170 lit.

A) 200 hrs | B) 240 hrs |

C) 300 hrs | D) 270 hrs |

Explanation:

Volume of water collected in the tank in 1 hour

⇒ (0.3 × 0.2 × 20km × 1000mts) = 1200 m cubic

If after t hours, the water is at height of 12m,

1200t=200×150×12

⇒ t = 300 Hours.

A) 32.5 hrs | B) 29.25 hrs |

C) 30.30 hrs | D) 31 hrs |

Explanation:

Let the leak will empty the tank in x hrs

Then,

1/9 - 1/x = 1/13

x = 29.25 hrs

A) 4 hrs 15 min | B) 3 hrs 24 min |

C) 4 hrs 51 min | D) 3 hrs 45 min |

Explanation:

Time taken by one tap to fill half of the tank = 3 hrs.

Part filled by the taps in 1 hour = 4 x 1/6 = 2/3

Remaining part = 1 - 1/2 = 1/2

2/3 : 1/2 :: 1 : p

p = 1/2 x 1 x 3/2 = 3/4 hrs. i.e., 45 min

So, total time taken = 3 hrs 45 min.