Important Formulas

1. If a person can do a work in n numbers of days, then the person's 1 day's work = 1/n

2. If a person's 1 day's work = 1/n, then the person can finish the work in n days.

3. If X is twice as good as a workman as Y, then

Ratio of work done by X and Y = 2 : 1

Ratio of times taken by X and Y to finish a job = 1 : 2