# 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 =$\frac{1}{n}$

**2. **If A’s 1 day's work =$\frac{1}{n}$, 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 :

$Efficiency\propto \frac{1}{Nooftimeunits}$

$\therefore Efficiency\times Time=Cons\mathrm{tan}tWork$

Hence, $Requiredtime=\frac{Work}{Efficiency}$

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 = $\frac{100}{Efficiency}$

A) 30 days | B) 40 days |

C) 10 days | D) 20 days |

A) 660/47 | B) 640/47 |

C) 680/47 | D) 665/47 |

A) 21/3 days | B) 48 days |

C) 40 days | D) 48/5 days |

Explanation:

Ans.

Time taken by A to complete a work alone - 24 days

Time taken by A in completing 1/3 of work = 24*1/3= 8 Days

8 day = time taken by B in completing 1/2 of work

B alone can complete the work = 16 days

The required time in completing the work if both A & B start working together?

16*24 / 40 = 48/5 Days