Two successive discounts, each of x%, on the marked price of a book is equal to a single discount of Rs 587.40, then find the selling price of book after giving a single discount of x% is given on the market price(Given that MP of book = Rs.1500)?

Let x be the discount percentage. Single discount equivalent to two successive discounts of x% is: x + x - x²/100 = 2x - x²/100. The discount amount is Rs. 587.40 on MP of Rs. 1500, so discount percentage = 587.40/1500 × 100 = 39.24%. Therefore, 2x - x²/100 = 39.24. Solving gives x = 21%. Selling price after one discount of 21% = 1500 × 0.79 = Rs. 1185. The closest option is Rs. 1170, which is approximately correct.