If the cost price of 12 pencils is equal to the selling price of 8 pencils, the gain percent is:	Choose one:
A) 30 B) 40 C) 50 D) 60 E) 70
C   50%   Let C.P. of each pencil be $ 1.   Then, C.P. of 8 pencils = $8; S.P. of 8 pencils = $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 pencils is equal to the selling price of 8 pencils, the gain percent is: