A book was sold at a 12% profit. If it had been bought at 10% less and sold for Rs. 5.75 more, the profit would have been 30%. Find the cost price. MCQ with Answer and Explanation

Let initial Cost Price = 100x. Initial Selling Price = 112x. New Cost Price = 90x. New Selling Price = 90x * 1.30 = 117x. Difference in Selling Price = 117x - 112x = 5x. 5x = 5.75. x = 1.15. Cost Price = 100 * 1.15 = 115.