**Solution:**

Let's assume the cost price of the first article is Rs. x.

**Profit on the first article:**
Profit% = 15%
Profit = (15/100) * x = 0.15x

Selling price of the first article = Cost price + Profit = x + 0.15x = 1.15x

Now, let's assume the cost price of the second article is Rs. y.

**Loss on the second article:**
Loss% = 13%
Loss = (13/100) * y = 0.13y

Selling price of the second article = Cost price - Loss = y - 0.13y = 0.87y

According to the problem, the total selling price of both articles is Rs. 15625.

Therefore, 1.15x + 0.87y = 15625 ----(1)

To find the overall profit% or loss%, we need to find the total cost price of the two articles.

**Finding the total cost price:**
From equation (1), we can rearrange it to solve for x:
1.15x = 15625 - 0.87y
x = (15625 - 0.87y) / 1.15 ----(2)

Substituting the value of x from equation (2) into equation (1):
1.15 * (15625 - 0.87y) / 1.15 + 0.87y = 15625
15625 - 0.87y + 0.87y = 15625
15625 = 15625

This means the equation is true for any value of y. Therefore, we can say that the total cost price of the two articles is constant, regardless of the values of x and y.

Since the total cost price remains constant, the overall profit% or loss% can be calculated by comparing the total selling price to the total cost price.

**Overall profit/loss percentage:**
Profit = Total Selling Price - Total Cost Price
Profit% = (Profit / Total Cost Price) * 100

In this case, the total selling price is Rs. 15625 and the total cost price is constant.

Profit% = (15625 - Total Cost Price) / Total Cost Price * 100

However, since the total cost price is constant, the profit% will always be zero. This means that there is neither an overall profit nor an overall loss in this scenario.

Therefore, the overall profit% or loss% is 0%.