Profit and Loss - General Questions

The cost price of 31 articles is equal to the selling price of 23 articles. What is the gain percent?

An article bought for Rs. 1,040 is sold for Rs. 1,092. What is the gain percent?

A man sold an article for Rs. 352 at a loss of 20%. What was the cost price?

A dishonest dealer professes to sell his goods at cost price but uses a weight of 920 g for a kilogram. What is his gain percent?

A dishonest dealer professes to sell his goods at cost price but uses a weight of 850 g for a kilogram. What is his gain percent?