A) 15 | B) 30 |

C) 25 | D) 10 |

Explanation:

Combined efficiency of all the three boats = 60 passenger/trip

Now, consider option(a)

15 trips and 150 passengers means efficiency of B1 =

which means in carrying 50 passengers B1 must has taken 5 trips. So the rest trips equal to 5 (10-5 = 5) in which B2 and B3 together carried remaining 250 (300 - 50 = 250) Passengers.

Therefore the efficiency of B2 and B3 =

Since, the combined efficiency of B1, B2 and B3 is 60. Which is same as given in the first statement hence option(a) is correct.

A) 3 | B) 6 |

C) 9 | D) 12 |

Explanation:

The mother completes the job in x hours.

So, the daughter will take 2x hours to complete the same job.

In an hour, the mother will complete 1/x of the total job.

In an hour, the daughter will complete 1/2x of the total job.

So, if the mother and daughter work together, in an hour they will complete 1/x + 1/2x of the job.

i.e., in an hour they will complete 3/2x of the job.

The question states that they complete the entire task in 6 hours if they work together.

i.e., they complete 1/6 th of the task in an hour.

Equating the two information, we get 3/2x = 1/6

By solving for x, we get 2x = 18 or x = 9.

The mother takes 9 hours to complete the job.

A) 47/7 days | B) 59/6 days |

C) 48/5 days | D) 57/5 days |

Explanation:

Amount of work K can do in 1 day = 1/16

Amount of work L can do in 1 day = 1/12

Amount of work K, L and M can together do in 1 day = 1/4

Amount of work M can do in 1 day = 1/4 - (1/16 + 1/12) = 3/16 – 1/12 = 5/48

=> Hence M can do the job on 48/5 days = 9 (3/5) days

A) 24 1/2 days | B) 25 3/2 days |

C) 24 2/3 days | D) 26 2/3 days |

Explanation:

1/3 ---- 8

1 -------?

Hari can do total work in = 24 days

As satya is 60% efficient as Hari, then

Satya = 1/24 x 60/100 = 1/40

=> Satya can do total work in 40 days

1 ----- 40

2/3 ---- ? => 26 2/3 days.

A) 4 days | B) 8 days |

C) 3 days | D) 6 days |

Explanation:

4/10 + 9/x = 1

=> x = 15

Then both can do in

1/10 + 1/15 = 1/6

=> 6 days

A) 2 days | B) 2.5 days |

C) 2.25 days | D) 3 days |

Explanation:

1 man's 1 day work = 1/108

12 men's 6 day's work = 1/9 x 6 = 2/3

Remaining work = 1 - 2/3 = 1/3

16 men's 1 day work = 1/108 x 16 = 4/27

4/27 work is done by them in 1 day.

1/3 work is done by them in 27/4 x 1/3 = 9/4 days.