By selling 100 pens, a trader gains the cost of 30 pens. Find his gain percentage?
Select:  A) 30%  B) 33%  C) 31%  D) 32%  E) 34%
Let the CP of each pen be Rs. 1.   CP of 100 pens = Rs. 100   Profit = Cost of 30 pens   = Rs. 30   Profit% = 30/100* 100= 
<gadget id="calculator">30/100* 100</gadget>
<output>30</output>
30%   30%nswer: 30%
<result>A</result>
By selling 100 pens, a trader gains the cost of 30 pens. Find his gain percentage?