22. A man buys 10 articles for Rs. 8 and sells them at the rate of Rs. 1.25 per article. His gain is:

23. By selling 8 dozen of pencils, a shopkeeper gains the selling price of 1 dozen pencils. His gain per cent is:

24. Aloke bought 25 kg of rice at the rate of Rs. 6 per kg and 35 kg of rice at the rate of Rs. 7 per kg. He mixed the two and sold the mixture at the rate of Rs. 6.75 per kg. What was his gain or loss in the transaction?