Important Maths Formulas of Time and Work
 If a person can finish a piece of work in ‘n’ days, then the work done by the person in 1 day is 1/n th part of the work.

 If a person completes 1/n th part of the work in 1 day, then the time taken by the person to finish the work is n days.

 If P can complete a piece of work in ‘a’ days and Q can complete the same piece of work ‘b’ days, both of them working together will take ab/(a +b) days to complete the same piece of work.

 If P and Q, working together, can complete a piece of work in ‘a’ days and P alone can complete the same piece of work in ‘b’ days, Q alone will complete the same piece of work in ab/(b  a) days.

 If P, Q and R can do a piece of work in ‘a’, ‘b’ and ‘c’ days, respectively, by working together, they will take abc/ (ab + bc + ca) days to complete the same piece of work.

 If P, Q and R can do a piece of work in ‘a’, ‘b’ and ‘c’ days, respectively, the portions of work done by them will be in the ratio of 1/a: 1/b: 1/c.
