Time and Work formula

1.If X completes a work in x days, then work done by X in one day is ¹/_x.

2. If work done by X in one day is ¹/_x, then time taken by X to complete the work is x days.

3. If If X completes a work in x days and Y completes a work in y days, then the work done by them working together in one day is ¹/_x + ¹/_y and time taken by both to complete the work together is ^xy/_(x+y) days.

4. Number of days required to complete the given work = ^{Total work to be done}/_{Work done in one day}.

5. N1H1D1E1W2 = N2H2D2E2W1

Where:

N1 and N2 = number of person

H1 and H2 = Hours worked by per person per day (assumed constant)

D1 and D2 = days

E1 and E2 = Efficiency

W1 and W2= Amount of work done