Topic Included: | Formulas, Definitions & Exmaples. |

Main Topic: | Quantitative Aptitude. |

Quantitative Aptitude Sub-topic: | Time and Work Aptitude Notes & Questions. |

Questions for practice: | 10 Questions & Answers with Solutions. |

Work efficiency (ability to do any work) of any person is inversely proportional to time.$$ Efficiency \propto \frac{1}{Time} $$

**Example (1):** The efficiency of worker P is twice than the worker Q. If P can finish a task before \(10 \ days\) than Q, then find how many days P needs to finish the task?

**Solution:** Let P can finish the task in \(x \ days\) and Q can finish the task in \(2x \ days\), but P can finish the task \(10 \ days\) before Q then, $$ 2x - x = 10 $$ $$ x = 10 \ days $$

P can finish the task in \(x \ days = 10 \ days\) and Q can finish the task in \(2x \ days = 20 \ days\).

**Example (2):** The efficiency of a man is thrice than a women. If the man can finish a task before \(6 \ days\) than the women, then find how many days the man needs to finish the task?

**Solution:** Let the man can finish the task in \(x \ days\) and women can finish the task in \(3x \ days\), but the man can finish the task \(6 \ days\) before the women then, $$ 3x - x = 6 $$ $$ x = 3 \ days $$

the man can finish the task in \(x \ days = 3 \ days\) and the women can finish the task in \(3x \ days = 3 \times 3 = 9 \ days\).

**Example (3):** P is two times as efficient as Q and finish a work \(16 \ days\) before Q, then find how many days required to finish the work if both are working simultaneously?

**Solution:** Let P can finish the work in \(x \ days\) and Q can finish the work in \(2x \ days\), then $$ 2x - x = 6 $$ $$ x = 6 \ days $$ $$ 2x = 12 \ days $$ together they can finish the work, $$ \frac{1}{6} + \frac{1}{12} $$ $$ = \frac{3}{12} = \frac{1}{4} $$ Hence they need \(4 \ days\) to finish the work.

Lec 1: Time and Work Case (1) and Case (2)
Exercise-1
Lec 2: Time and Work Case (3) and Case (4)
Exercise-2
Lec 3: Concept of Positive and Negative work
Exercise-3
Lec 4: Concept of Pipes and Cisterns
Exercise-4
Lec 5: Concept of Efficiency
Exercise-5