A number whose fifth part increase by 4 is equal to its fourth part diminished by 10, is :

Answer: Option D

Let the number be x
Then,
$$\begin{array}{rl}& \iff \frac{x}{5}+4=\frac{x}{4}-10\\ & \iff \frac{x}{4}-\frac{x}{5}=14\\ & \iff \frac{x}{20}=14\\ & \iff x=14\times 20\\ & \iff x=280\end{array}$$