C.P of 12 pens = S.P. of 8 pens.Calculate the gain percentage.Options50%70%120%60%

Let's solve this step by step:

Step 1: From the given problem, we know that the cost price (C.P) of 12 pens is equal to the selling price (S.P) of 8 pens.

Step 2: Let's assume the cost price of one pen is x. Therefore, the cost price of 12 pens is 12x.

Step 3: Similarly, let's assume the selling price of one pen is y. Therefore, the selling price of 8 pens is 8y.

Step 4: According to the problem, 12x = 8y.

Step 5: Simplifying this, we get the ratio of selling price to cost price, y/x = 12/8 = 1.5.

Step 6: The gain percentage is calculated as (S.P - C.P)/C.P * 100. Substituting y/x for S.P/C.P, we get (1.5 - 1)/1 * 100 = 50%.

So, the gain percentage is 50%.