RBI Grade B Officers 2016 Sep shift 1 Paper

A shopkeeper purchased 15 kg of variety A rice at Rs. x per kg and 10 kg of variety B rice at Rs. ‘x + 5’ per kg. The shopkeeper sold the whole quantity of variety A rice at 10% profit and that of variety B rice at 20% profit. The total selling price of variety A rice was Rs. 30 more than that of variety B rice. Had the two varieties been mixed and sold at an overall profit of 20%, what would have been the selling price (per kg)?