Question

A factory requires 42 machines to produce a given number of articles in 63 days. How many machines would be required to produce the same number of articles in 54 days?

Answer 1

Let the number of machines required be x.
$\begin{array}{ccc}\text{Days}& 63& 54\\ \text{Machines}& 42& x\end{array}$
Here, the number of machines and the number of days are in inverse proportion.
$\therefore \frac{63}{54}=\frac{x}{42}$
$\Rightarrow x\times 54=63\times 42$
$\Rightarrow x=\frac{63\times 42}{54}=49$
Hence, 49 machines would be required.