# 39 Persons Can Repair a Road in 12 Days Working 5 Hours a Day. In How Many Days will 30 Persons Working 6 Hours a Day Complete the Work?

### Computer MCQs Series for PPSC, FPSC – Most Repeated MCQs | Set 6

• 39 persons can repair a road in 12 days working 5 hours a day.
• The days required to complete the work by 30 persons working 6 hours a day can be figure out in this way.

## Explanation

Three given entities here are

1. Person
2. Hours
3. Days

To determine the relation here, let suppose; The days required to complete the work by 30 persons working 6 hours a day = y

Case I

Person        Days

39               12

30               y

• More persons mean less days to get the job done.
• Less persons mean more days to complete the job.

This clearly indicates that there is inverse relation.

Direct/Indirect relation tells how the equation will be written.

39 : 30  ::  y : 12 ________ (i)

Case II

Hours         Days

5                 12

6                 y

• Less hours mean more days.
• More hours mean less days.

This clearly indicates that there is also inverse relation.

Direct/Indirect relation tells how the equation will be written.

5 : 6  ::  y : 12 ________ (ii)

By (i) and (ii)

39 : 30 :: y : 12

5 : 6

39 x 5 x 12 = 30 x 6 x y ________ (A)

After simplifying equation (A), we can easily figure out the value of y (y = 13)

## To Find

The days required to complete the work by 30 persons working 6 hours a day = ?

## Solution

### Method I

Let suppose

The days required to complete the work by 30 persons working 6 hours a day = y

Person        Hours         Days

39               5                 12

30               6                 y

• Relation between persons and days is inverse.
• Relation between hours and days is also inverse so;

39 : 30 :: y : 12

5 : 6

39 x 5 x 12 = 30 x 6 x y

2340 = 180y

2340/180 = y

13 = y

y = 13 days

The days required to complete the work by 30 persons working 6 hours a day = 13 days answer

### Method II

The days required to complete the work by 39 persons working 5 hours a day = 12 days

The days required to complete the work by 39 persons working 1 hours a day = (12 x 5) days

The days required to complete the work by 1 person working 1 hours a day = (12 x 5 x 39) days

The days required to complete the work by 1 persons working 6 hours a day = 2340/6 days

The days required to complete the work by 1 persons working 6 hours a day = 390 days

The days required to complete the work by 30 persons working 6 hours a day = 390/30 days

The days required to complete the work by 30 persons working 6 hours a day = 13 days

The days required to complete the work by 30 persons working 6 hours a day = 13 days answer

### Conclusion

39 persons can repair a road in 12 days working 5 hours a day. In 13 days, 30 persons working 6 hours a day can complete the work.