If a number is added to two-fifths of itself, the value so obtained is 455. What is the number ?

Answer: Option A

Let the number be x
Then,
$$\begin{array}{rl}& \iff x+\frac{2}{5}x=455\\ & \iff \frac{7}{5}x=455\\ & \iff x=\left(\frac{455\times 5}{7}\right)\\ & \iff x=325\end{array}$$