The sale price of an article including the sales tax is Rs. 1232. The rate of sales tax is 10%. If the shopkeeper has made a profit of 12%, then the cost price of the article is = ?

Answer: Option C

Let the cost price of article be Rs. x
Profit = 12%
Rate of sales tax = 10%
Sale price of an article including sales tax = Rs. 1232
According to the question,
$$\begin{array}{rl}& \Rightarrow \frac{112x}{100}+\frac{112x\times 10}{10000}=1232\\ & \Rightarrow \frac{1120x+112x}{1000}=1232\\ & \Rightarrow 1232x=1232\times 1000\\ & \Rightarrow x=\text{Rs}\text{. }1000\end{array}$$