Allen sells stationery items in his shop. Since the sales was going on in a very slow process, he decreased the prices of the products by $10\%$. There by the number of products sold increased by $30\%$. What is the increase in the total revenue ?

Question

$\begin{array}{1 1} (a)\; 23\\(b)\;16 \;\;2/3 \\(c)\; 15\\(d)\;17 \end{array}$