If the cost price of 12 pens is equal to the selling price of 8 pens, the gain percent is:	Choices:
A) 9%
B) 26%
C) 50%
D) 80%
E) 34%
C   C.P. of each pen be Re. 1.   Then, C.P. of 8 pens = Rs. 8; S.P. of 8 pens = Rs. 12.   Gain % = 4/8 * 100= 
<gadget id="calculator">4/8 * 100</gadget>
<output>50</output>
50%
<result>C</result>
If the cost price of 12 pens is equal to the selling price of 8 pens, the gain percent is: