A dishonest dealer defrauds to the extent of x% in buying as well as selling is goods by using faulty weight. What will be the gain percent on his outlay?

Explanation:-

$$\eqalign{ & {\text{Total profit}} \cr & = x + x + \frac{{x \times x}}{{100}} \cr & = \left( {2x + \frac{{{x^2}}}{{100}}} \right)\% \cr}$$