The cost price of 18 articles is equal to the selling price of 15 articles. The gain percent is?Options15%25%18%20%

Let's solve this step by step:

Step 1: Understand the problem The cost price of 18 articles is equal to the selling price of 15 articles. This means that the seller is making a profit because they are selling less articles for the same price they bought more articles.

Step 2: Set up the equation Let's denote the cost price of one article as CP and the selling price of one article as SP. According to the problem, we have the equation:

18CP = 15SP

Step 3: Solve for SP We can rearrange the equation to solve for SP:

SP = 18*CP / 15

Step 4: Calculate the profit The profit is the selling price minus the cost price, so:

Profit = SP - CP Profit = 18*CP / 15 - CP

Step 5: Calculate the profit percentage The profit percentage is the profit divided by the cost price, times 100%, so:

Profit% = Profit / CP * 100% Profit% = (18*CP / 15 - CP) / CP * 100% Profit% = (18/15 - 1) * 100% Profit% = 3/15 * 100% Profit% = 20%

So, the gain percent is 20%.