The profit percentage of P and Q is same on selling the articles at Rs. 1800 each but A calculates his profit on the selling price while Q calculates it correctly on the cost price which is equal to 20%. What is the difference in their profits?

A man buys 12 articles for Rs. 12 /- and sells them at the rate of Rs.1.25 per article. His gain percentage is: 

A tradesman marks his goods at 20 % above the cost price. He allows his customers a discount of 8% on marked price. Find out his profit percent.

A man sells an article at 5 % above its cost price. If he had bought it at 5 % less than what he had paid for it and sold it at Rs. 2 less, he would have gained 10 %. The cost price of the article is