The difference between successive discounts of 40% followed by 30% and 45% followed by 20% on the marked price of an article is Rs. 12. The marked price of the article is = ?

Answer: Option C

According to first condition total discount
$$\begin{array}{rl}& =a+b-\frac{ab}{100}\\ & =40+30-\frac{40\times 30}{100}\\ & \text{ = 70}-\text{12}\\ & =58\end{array}$$
In first condition total discount = 58%
In second condition total discount
$$=45\%+20\%-\frac{45\times 20}{100}$$
Total discount = 56%
According to the question,
58% - 56% = Rs. 12
2% = 12
1% = 6
100% = 600
∴ Marked price will be Rs. 600