A dishonest grocer sells rice at a profit of 10% and uses weight which are 20% less than the marked weight. The total gain earned by him will be = ?

Answer: Option A

According to the question,
Grocer use 20% less weight
= 1000 - 200
= 800 gm.
$$\begin{array}{rl}& \text{The profit }\%\\ & =\frac{200}{800}\times 100\\ & =25\%\\ & \text{Then total profit }\\ & =10+25+\frac{25\times 10}{100}\\ & =37.5\%\end{array}$$