19) The cost price of 20 articles is the same as the selling price of x articles. If the profit is 25%, then the value of x is:

Step 1: Let's denote the cost price of one article as C.

Step 2: According to the problem, the cost price of 20 articles is the same as the selling price of x articles. So, we can write this as 20C = xS, where S is the selling price of one article.

Step 3: The problem also states that the profit is 25%. Profit is calculated as the selling price minus the cost price. So, we can write this as S = C + 0.25C = 1.25C.

Step 4: Now, we can substitute S from step 3 into the equation from step 2: 20C = x(1.25C).

Step 5: Solving for x, we get x = 20 / 1.25 = 16.

So, the value of x is 16.