If the cp of 12 rubbers is equal to the sp of 8 rubbers, the gain %is ?	Choose the correct choice:
A) 25%
B) 30%
C) 50%
D) 70%
E) 80%
(Explanation:Friends, we know we will need gain amount to get gain percent, right.   So lets get gain first.   Let the cost price of 1 pen is Re 1 50%ost of 8 pens = Rs 8 Selling price of 8 pens = 12   Gain = 12 - 8= 
<gadget id="calculator">12 - 8</gadget>
<output>4</output>
4 Gain%=(Gain50%ost*100)%=(48*100)%=50%   50%
<result>C</result>
If the cp of 12 rubbers is equal to the sp of 8 rubbers, the gain %is ?