Let us take the Task to be Done as : T
Given : 6 Workers complete the task in 12 days
6 Workers do a Work of [tex]\frac{T}{12}[/tex] in One Day
If the Task is needed to be completed in 4 days :
Each Day [tex]\frac{T}{4}[/tex] work should be Done
We found that :
6 Workers do a Work of [tex]\frac{T}{12}[/tex] in One Day
6 × 3 Workers do a Work of [tex]\frac{3T}{12}[/tex] in One Day
18 Workers do a Work of [tex]\frac{T}{4}[/tex] in One Day
18 Workers do a Work of T in 4 Days