Important notes and formula

### One day's work

If a person can do a piece of work in N days. Then the person's 1 day's work = (1/N).

Example:

If a person paints a 2000 sq. feet wall in 5 days. Then the person's 1 day's work = (1/5).

### Time to finish a work

If a person's 1 day's work is 1/N then, the person can finish the work in N days.

Example:

If a person's 1 day's work is 1/5 then, the person can finish the work in 5 days.

### Efficiency Ratio

If person A is twice as efficient as person B then,

ratio of work done by A and B = 2 : 1

ratio of time taken to complete the work by A and B = 1 : 2

If person A is five times as efficient as person B then,

ratio of work done by A and B = 5 : 1

ratio of time taken to complete the work by A and B = 1 : 5