- Some persons can do a piece of work in 12 days.
- Days taken by two times the number of such person to do half of the work will be figure out in this way.
Explanation
Two given entities here are
- Person
- Days
To determine the relation here, let suppose; Days taken by two times the number of such person to complete the work = y
Case
Let suppose
Some persons = 10
Two times the number of such person = 20
Person Days
10 12
20 y
- More persons mean less days.
- Less persons mean more days.
This clearly indicates that there is inverse relation.
Direct/Indirect relation tells how the equation will be written.
10 : 20 :: y : 12 ________ (i)
20 x y = 10 x 12 ________ (A)
After simplifying equation (A), we can easily figure out the value of y (y = 6 and to do half of the work = 6/2 = 3 days)
To Find
Days taken by two times the number of such person to do half of the work = ?
Solution
Method I
Let suppose
Days taken by two times the number of such person to complete the work = y
Person Days
10 12
20 y
- Relation between person and days is inverse.
So
10 : 20 :: y : 12
20 x y = 10 x 12
20y = 120
y = 120/20
y = 6 days
Days taken by two times the number of such person to complete the work = 6 days
Days taken by two times the number of such person to do half of the work = 6/2
Days taken by two times the number of such person to do half of the work = 3 days answer
Method II
Let suppose
Some persons = 10
Two times the number of such person = 20
Days taken by 10 persons to complete the work = 12 days
Days taken by 1 person to complete the work = (12 x 10) days
Days taken by 1 person to complete the work = 120 days
Days taken by 20 person to complete the work = 120/20 days
Days taken by 20 person to complete the work = 6 days
Days taken by two times the number of such person to complete the work = 6 days
Days taken by two times the number of such person to do half of the work = 6/2
Days taken by two times the number of such person to do half of the work = 3 days answer
Conclusion
Some persons can do a piece of work in 12 days. Two times the number of such person will do half of that work in 3 days.
