Rules for Solving the Problems based on Time and Work

1) If a person can complete a work in n  days, then in 1 day he does  n^{th} of the work. We have

A\ Person's \ 1\ Day\ Work= \frac{1}{Total\ number\ of\ days\ to\ complete\ the\ work}

2) If a person completes of a work in 1 day, then he requires n  number of days to complete the work

Total\ no. \ of\ days\ to\ complete\ the\ work= \frac{1}{A \ Person's \ 1\ Day\ Work}

3) If part of the work has been done and the remaining part of the work has to be done by a person A, then

No. \ of\ days \ to\ complete\ the\ work= \frac{Remaining\ Part\ of\ the\ Work}{A's\ 1\ Day\ Work}

4) If A\ is\ m times as good ·a workman as B , then

i) Ratio of work done by A \ and\  B in the same time = m : 1

ii) Ratio of time taken by A \ and\  B to finish the work =1: m

5) If some persons work together to do a piece of work, then the money paid to them is divided among them in the ratio of their one day’s (or one hour’s) work.