If selling price of 12 pens is equal to the cost price of 18 pens,find the profit percent.

Step 1: Let's assume the cost price of one pen is $1. Therefore, the cost price of 18 pens would be$18.

Step 2: According to the problem, the selling price of 12 pens is equal to the cost price of 18 pens, which is $18. So, the selling price of one pen would be$18/12 = $1.5.

Step 3: Now, we can calculate the profit made on one pen. The profit would be the selling price of one pen minus the cost price of one pen, which is $1.5 -$1 = $0.5.

Step 4: The profit percentage is calculated as (Profit/Cost price) * 100. Substituting the values we have, the profit percentage would be ($0.5/$1) * 100 = 50%.

So, the profit percent is 50%.