Question

In a dairy farm, 40 cows eat 40 bags of husk in 40 days. In how many days one cow will eat one bag of husk?

• A. 1
• B. $\frac{1}{40}$
• C. 40
• D. 80

Answer 1

The correct option is C 40

Let the required number of days be x.
Less cows, More days (Indirect Proportion)
Less bags, Less days (Direct Proportion)
$\begin{array}{cc}Cow& 1:40\\ Bags& 40:1\end{array}\}::40:x$
$\therefore 1\times 40\times x=40\times 1\times 40$
$\Rightarrow x=40$