Discussion Forum

If 15 men, working 9 hours a day, can reap a field in 16 days, in how many days will 18 men reap the field, working 8 hours a day ?

Answer:

Explanation:

Let the required number of days be $x$

More men, Less days               (Indirect Proportion)

Less hours per day, More days   (Indirect Proportion)

$\left\{\begin{array}{c}Men\quad\quad\quad 18:15\\ Hours/Day\quad 8:9\end{array}\right\}::16:x$

$ \therefore(18\times 8\times x)=(15\times 9\times 16)$

$\Leftrightarrow x=\frac{15\times 144}{144}$ $=15$

Hence, required number of days = 15.