A) 9 | B) 10 |

C) 11 | D) 12 |

Explanation:

Let the required no of working hours per day be x.

More pumps , Less working hours per day (Indirect Proportion)

Less days, More working hours per day (Indirect Proportion)

X= x=12

A) 40 | B) 50 |

C) 60 | D) 70 |

Explanation:

Let the required no of hours be x. Then

Less men , More hours (Indirct Proportion)

15:36 ::25:x (15 x X)=(36 x 25)

Hence, 15 men can do it in 60 hours.

A) 46 | B) 47 |

C) 48 | D) 49 |

Explanation:

Let the required length be x meters

More men, More length built (Direct proportion)

Less days, Less length built (Direct Proportion)

(20 x 6 x X)=(35 x 3 x 56)

Hence, the required length is 49 m.

A) 18 days | B) 21 days |

C) 24 days | D) 30 days |

Explanation:

5 men= 10 boys 1man= 2 boys

(2 men+ 7 boys) = (2 x 2 +7) boys = 11 boys

( 8 men + 6 boys) = (8 x 2 +6) boys = 22 boys.

Let the required number of days be x.

More boys , Less days (Indirect proportion)

More work , More days (Direct proportion)

Hence, the required number of days = 21

A) 3 | B) 5 |

C) 6 | D) 9 |

Explanation:

men can finish the work in 1 day

4500 men can finish the work in 1 day. 100 men can finish it in = 45 days.

This is 5 days behind Schedule

A) 75 | B) 82 |

C) 100 | D) 110 |

Explanation:

Originally let there be x men.

Less men, More days (Indirect Proportion)

(x-10) : x :: 100 :110 10x= 1100 x= 110