Question:
A number whose fifth part increased by 5 is equal to its fourth part diminished by 5. Find the number.
Solution:
Let the number be $\mathrm{x}$.
According to the question,
$\frac{\mathrm{x}}{5}+5=\frac{\mathrm{x}}{4}-5$
or $\frac{\mathrm{x}}{5}-\frac{\mathrm{x}}{4}=-5-5$
or $\frac{4 \mathrm{x}-5 \mathrm{x}}{20}=-10$
or $-\mathrm{x}=-200[$ After cross multiplication $]$
or $x=200$
Thus, the number is 200 .