Question

$6$ men can complete the electric fitting in a building in $7$ days. How many days will it take it to take $21$ men to do the job?

Answer 1

Let the no.of days be $x.$

No.of men $6$ $21$

No.of days $7$ $x$

It is the case of inverse variation

$21x=7\times 6$

$\Rightarrow x=\frac{7\times 6}{21}$

$\Rightarrow x=2$ days.