The marked price of an article is Rs 400. It is sold for Rs 300. If there is a loss of 15%, then by what percent above the cost is the article marked?

13.33%

Marked price = Rs 400, Selling price = Rs 300

If there is loss of 15%, CP = $\frac{100}{85}$ SP

⇒  CP = $\frac{100}{85}$ 300 = 352.941

The article is marked above the cost price by $\frac{47.059}{352.941}$ x 100 i.e. 13.33%