# Time and Work- QA Formulae

By Aditi Joshi|Updated : September 26th, 2022

The basic type of questions that may be asked in the exam about time and work are given below:

• Find the efficiency of a person.
• Find the time taken by an individual to do a piece of work.
• Find the time taken by a group of individuals to complete a piece of work.
• Find the work done by an individual in a certain time duration.
• Find the work done by a group of individuals in a certain time duration.

Work: Amount of job assigned or the amount of job actually done

Relations between work, time, and person:

• Work and person: Directly proportional, i.e., more work, more person required.
• Time and person: Inversely proportional, i.e., more people, less time required
• Work and time: Directly proportional, i.e., more work, more time required

Rules:

• If a person’s one day’s/hour’s work = 1/n, then they will complete the work in ‘n’ days/hours.
• If the first person is ‘n’ times more efficient than the second person, then the ratio of work done by the first person to the second person = n:1
• If the ratio of the number of men required to complete a work is m:n, then the ratio of time taken by them will be n:m.

Formulas and quick tricks for time and work:

• If 1/n part of a work is done by A in one day, then A will take n days to complete the full work.
• If A can do a piece of work in X days and B can do the same work in Y days, then together they can do the same work in • If A, B, and C, alone can complete a work in X, Y, and Z days, respectively, then together they will complete the work in days
• If A and B together can finish a piece of work in X days, B and C in Y days and C and A in Z days, then
1- A, B, and C together can finish the job in 2- A alone will finish the job in 3- B alone will finish the job in 4- C alone will finish the job in If A can finish a work in X days and B is k times more efficient than A, then the time taken by both A and B working together to complete the work is  GradeStack Learning Pvt. Ltd.Windsor IT Park, Tower - A, 2nd Floor, Sector 125, Noida, Uttar Pradesh 201303 help@byjusexamprep.com