Question:
Find the number whose fifth part increased by 5 is equal to its fourth part diminished by 5.
Solution:
Let the number be $\mathrm{x}$.
Fifth part increased by $5=\frac{\mathrm{x}}{5}+5$
Fourt part diminished by $5=\frac{x}{4}-5$
$\therefore \frac{x}{5}+5=\frac{x}{4}-5$
$\Rightarrow 5+5=\frac{x}{4}-\frac{x}{5}$
$\Rightarrow 10=\frac{5 x-4 x}{20}$
$\Rightarrow 10=\frac{x}{20}$
$\Rightarrow 200=x$
$\Rightarrow x=200$
Therefore, the number is 200 .