Question

If $45$ men can do a piece of work in $15$ days, in how many days will $9$ men do it?

• A. $75$ days
• B. $60$ days
• C. $45$ days
• D. $30$ days

Answer 1

The correct option is A $75$ days

Let $x$ be the number of days in which $9$ men can do a piece of work.

$\text{Number of men}$	$45$	$9$
$\text{Number of days}$	$15$	$x$

Since the number of men hired and the number of days taken to do a piece of work are in inverse variation, we have
$45\times 15=9\times x$
$\Rightarrow x=\frac{45\times 15}{9}=75$

Thus, the required number of days is $75$