Time and Work

Basics :

1. M1D1W2 = M2D2W1 (M-man, D-Day, W-Work).

2. If A can do a piece of work in x days, then

A’s 1 day work = 1/x.

3. If A’s 1-day work = 1/x, then A can finish a piece of work in x days.

4. If A is X times as good a workman as B then:

Ratio of work done by A and B = _X : 1

Ratio of time taken by A and B to finish a work = _1 : X.

Special Rules:

• If A can do a piece of work in x days and B can do it in y days then A and B working together will do the same work in xy/(x+y) days.
• If A and B together can do a piece of work in Y days and A can do it in X days then B working alone will do the same work in xy/(x-y) days.

|| Basics || Solved examples || Practice questions ||