A man sells an article at a profit of 25%. If he had bought it at 20% less and sold it for Rs.6.30 less, he would have gained 30%. Find the cost of the article.	Choose the correct choice from the following:	A) 30	B) 40	C) 50	D) 60	E) 70

Rationale: "let c . p = 100 gain = 25 % s . p = 125 supposed c . p = 80 gain = 30 % s . p = ( 130 * 80 ) / 100 = 104 diff = ( 125 - 104 ) = 21 diff 21 when c . p = 100 then diff 6.30 when c . p = ( 100 * 6.30 ) / 21 = 30 answer : a"
Answer: A