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Example 2: If a person can complete his work in 5days. What will be his efficiency?

Solution: Number of days a person take to complete his work = 5

⇒ He is doing 1/5 th work per day (converted into fraction)

Convert it into percentage:

100/5 = 20%

Therefore, his efficiency is 20%.

Summarizing, If a person can do his job in n days, efficiency will be

Efficiency = %

Note: Negative efficiency cancels the positive efficiency

For Example: Positive efficiency = 5%

Negative efficiency = 1.5%

Net efficiency = 5- 1.5 = 3.5%

As we all know, in competitive exams time management is very important. I suggest you to learn the

fractions till 15.

Number of days required to

complete work

Work/Day Efficiency (%)

N 1/n 100/n

1 1 100

2 1/2 50

3 1/3 33.33

4 1/4 25

5 1/5 20

6 1/6 16.66

7 1/7 14.28

8 1/8 12.5

9 1/9 11.11

10 1/10 10

11 1/11 9.09

12 1/12 8.25

13 1/13 7.69

14 1/14 7.14

15 1/15 6.66

Example 3: A can do a job in 10 days. B can do a job in 5 days. In how many days they can complete

the job if they work together?

Solution: Consider the above table

A’s efficiency = 10%

B’s efficiency = 20%

A+ B efficiency = 10 + 20 = 30%

This means, In one day A and B together can do 30% of work.

Therefore, Number of days A and B together take to do 100% of work =

⇒3.33 days

Example 2: If a person can complete his work in 5days. What will be his efficiency?

Solution: Number of days a person take to complete his work = 5

⇒ He is doing 1/5 th work per day (converted into fraction)

Convert it into percentage:

100/5 = 20%

Therefore, his efficiency is 20%.

Summarizing, If a person can do his job in n days, efficiency will be

Efficiency = %

Note: Negative efficiency cancels the positive efficiency

For Example: Positive efficiency = 5%

Negative efficiency = 1.5%

Net efficiency = 5- 1.5 = 3.5%

As we all know, in competitive exams time management is very important. I suggest you to learn the

fractions till 15.

Number of days required to

complete work

Work/Day Efficiency (%)

N 1/n 100/n

1 1 100

2 1/2 50

3 1/3 33.33

4 1/4 25

5 1/5 20

6 1/6 16.66

7 1/7 14.28

8 1/8 12.5

9 1/9 11.11

10 1/10 10

11 1/11 9.09

12 1/12 8.25

13 1/13 7.69

14 1/14 7.14

15 1/15 6.66

Example 3: A can do a job in 10 days. B can do a job in 5 days. In how many days they can complete

the job if they work together?

Solution: Consider the above table

A’s efficiency = 10%

B’s efficiency = 20%

A+ B efficiency = 10 + 20 = 30%

This means, In one day A and B together can do 30% of work.

Therefore, Number of days A and B together take to do 100% of work =

⇒3.33 days