A) 7 hrs | B) 7.5 hrs |

C) 8 hrs | D) 8.25 hrs |

Explanation:

Let there are L men

job requires LK man hours.

job completed in first 4 hrs = Lx4 = 4L

job completed in next 4 hrs = 4xL/2 = 2L

job completed in next 4 hrs = 4xL/4 = L

job completed in last 4 hrs = 4xL/8 = L/2

4L + 2L + L + L/2 = KL

K = 7+1/2 = 7.5 hours.

A) 16 days | B) 13 days |

C) 15 days | D) 12 days |

Explanation:

Ratio of times taken by P & Q = 100 : 130 = 10:13

Let Q takes x days to do the work

Then, 10:13 :: 23:x

=> x = 23x13/10

=> x = 299/10

P's 1 day's work = 1/23

Q's 1 day's work = 10/299

(P+Q)'s 1 day's work = (1/23 + 10/299) = 23/299 = 1/13

Hence, P & Q together can complete the work in **13** days.

A) 3 days | B) 6 days |

C) 4 days | D) 2 days |

Explanation:

From the given data,

=> (2 M + 3W) 8 = (3M + 2W)7

=> 16M + 24W = 21M + 14 W

=> 10W = 5M

=> 2W = M

=> 14W × **?** = 7W × 8

**?** = **4 days**

A) 16 | B) 18 |

C) 19 | D) 21 |

Explanation:

clearly total persons are increased in => 28/35 :: 52/65 = 4:5

As time is inversely proportional to men, so total **time** will decrease in the ratio 5:4

Hence, 22.5 x 4/5 = 18 days.

A) 8/15 | B) 7/9 |

C) 6/13 | D) 4/11 |

Explanation:

P's 1 day's work = | 1 | |

15 |

Q's 1 day's work = | 1 | |

20 |

(P + Q)'s 1 day's work = | 1 | + | 1 | = | 7 | |||

15 | 20 | 60 |

(P + Q)'s 4 day's work = | 7 | x 4 | = | 7 | |||

60 | 15 |

Therefore, Remaining work = | 1 - | 7 | = | 8 | . | ||

15 | 15 |

A) 1/3 | B) 2/3 |

C) 1/6 | D) 5/6 |

Explanation:

Given X can do in 10 days

=> 1 day work of X = 1/10

Y can do in 15 days

=> 1 day work of Y = 1/15

1day work of (X + Y) = 1/10 + 1/15 = 1/6

Given they are hired for 5 days

=> 5 days work of (X + Y) = 5 x 1/6 = 5/6

Therefore, **Unfinished work = 1 - 5/6 = 1/6 **