Answer :
Given that the 3 persons could rewire the house in 4 days and let x time is taken by 4 persons if used instead of three
Clearly we can see that more is the number of persons, less is the number of days required.
So, it is a case of inverse proportion.
∴ \(4 \times 3 = x \times 4\)
\(\Rightarrow x= \frac { 4\times 3 }{ 3 } = 3\)
Hence, the job will be completed in 3 days.