A number whose fifth part increased by 4 is equal to its fourth part diminished by 10. The number is:
Answer: C
Let the number be x.
The equation is \(\frac{x}{5} + 4 = \frac{x}{4} - 10\).
\(4 + 10 = \frac{x}{4} - \frac{x}{5}\).
\(14 = \frac{5x - 4x}{20}\).
\(14 = \frac{x}{20}\).
\(x = 14 \times 20 = 280\).