# Time and Work Questions

**FACTS AND FORMULAE FOR TIME AND WORK QUESTIONS**

**1. **If A can do a piece of work in n days, then A's 1 day's work =

**2. **If A’s 1 day's work =, then A can finish the work in n days.

**3. **A is thrice as good a workman as B, then:

Ratio of work done by A and B = 3 : 1.

Ratio of times taken by A and B to finish a work = 1 : 3.

NOTE :

Hence,

Whole work is always considered as 1, in terms of fraction and 100% , in terms of percentage.

In general, number of day's or hours =

A) 48 min | B) 54 min |

C) 30 min | D) none of these |

Explanation:

**In ideal Case:**

Time taken to fill the half tank by A and B = = hours

Time taken by A,B and C to fill rest half of the tank = = 3 hours

Total time = = 4 hours 12 min

**In second case:**

** **Time taken to fill tank by A and B = hours

Time taken by A,B and C to fill rest tank = hours

Total time = =3 hours 18 min

Therefore , difference in time = 54 minutes

A) 4 days | B) 5 days |

C) 6 days | D) 7 days |

Explanation:

Work donee by A and B in the first two hours, working alternatively = First hour A + Second hour B = (1/4) + (1/12) = 1/3.

Thus, the total time required to complete the work = 2 (3) = 6 days

A) A | B) B |

C) C | D) can't be determined |

Explanation:

A + B= 70%

B + C =50%

B= 20% A= 50% and C=30%

Hence A is most efficient

A) 4:18 pm | B) 3:09 pm |

C) 12:15 pm | D) 11:09 am |

Explanation:

Efficiency of P= 5%

Efficiency of Q= 4%

Efficiency of R= 2.5%

Efficiency of S= 2%

%

Thus, at 10 am pipe P,Q and R filled 30.5% of the cistern.

Now, the time taken by P,Q,R and S together to fill the remaining capacity of the cistern

= = =5 Hours and 9 minutes(approx)

Therefore, total time =4 hrs + 5hrs 9 mins

= 9 hrs and 9 mins

It means cistern will be filled up at 3:09 pm