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) 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.

A) 15 min 20 sec. | B) 16 min 40 sec. |

C) 13 min 10 sec. | D) 14 min 40 sec. |

Explanation:

Part filled in 4 minutes = 4(1/15 + 1/20) = 7/15

Remaining part = 1 - 7/15 = 8/15

Part filled by B in 1 minute = 1/20

1/20 : 8/15 :: 1 : k

k = 8/15 x 1 x 20 = 10 2/3 min = 10 min 40 sec.

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

A) 8.21 min | B) 8 min |

C) 8.57 min | D) 8.49 min |

Explanation:

1/10 + 1/15 = 1/6 x 3 = 1/2

1 - 1/2 = 1/2

1/10 + 1/15 - 1/x = 1/2

x = 8.57 min

A) 21 min | B) 24 min |

C) 20 min | D) 22 min |

Explanation:

Let the pipe B be closed after 'K' minutes.

30/16 - K/24 = 1 => K/24 = 30/16 - 1 = 14/16

=> K = 14/16 x 24 = 21 min.

A) 20 hrs | B) 28 hrs |

C) 36 hrs | D) 40 hrs |