By selling 90 pens, a trader gains the cost of 15 pens. Find his gain percentage?	Choose the correct choice from the following options:
A) 16.66%	B) 17.66%	C) 18.66%	D) 19.66%	E) 20.66%
Let the CP of each pen be Rs. 1.   CP of 90 pens = Rs. 90   Profit = Cost of 15 pens = Rs. 15   Profit% = 15/90 * 100 = 16.66%   16.66%nswer:16.66%
<result>A</result>
By selling 90 pens, a trader gains the cost of 15 pens. Find his gain percentage?