If the cost price of 50 articles is equal to the selling price of 40 articles, then the gain or loss percent is?	Choose the correct answer
A) 33%	B) 29%	C) 25%	D) 55%	E) 39%
C   25%   Given that, cost price of 50 article is equal to selling price of 40 articles.   Let cost price of one article = Rs. 1   Selling price of 40 articles = Rs. 50   But Cost price of 40 articles = Rs. 40   Therefore, the trader made profit.\Percentage of profit = 10/40 * 100= 
<gadget id="calculator">10/40 * 100</gadget>
<output>25</output>
25%
<result>C</result>
If the cost price of 50 articles is equal to the selling price of 40 articles, then the gain or loss percent is?