A) 6 hrs | B) 20/3 hrs |

C) 7 hrs | D) 15/2 hrs |

Explanation:

Now, it is the turn of A and B (3/20) part is filled by A and B in 1 hour.

therefore, Total time taken to fill the tank =(6+1)hrs= 7 hrs

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.

A) 31 min | B) 29 min |

C) 28 min | D) 30 min |

Explanation:

Part filled by (A + B) in 1 minute = (1/60 + 1/40) = 1/24

Suppose the tank is filled in x minutes.

Then, x/2(1/24 + 1/40) = 1

(x/2) x (1/15) = 1 => x = 30 min.

A) 32 hrs | B) 24 hrs |

C) 28 hrs | D) 26 hrs |

Explanation:

1/K + 1/L + 1/M = 1/8 (Given)

Also given that K = 2L and L = 2M

=> 1/2L + 1/L + 2/L = 1/8

=> (1 + 2 + 4)/2L = 1/8

=> 2L/7 = 8

=> L = 28 hours.