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