Let's denote the cost price of the article for Latif as \( x \).
Latif sells the article to Raza at a gain of 25%. This means Raza's purchase price is calculated as follows:
\[ \text{Selling price for Raza} = x + 0.25x = 1.25x \]
Raza then sells the article to Rashid at a gain of 20%. Therefore, Rashid's purchase price is:
\[ \text{Selling price for Rashid} = 1.25x + 0.20 \times 1.25x = 1.25x + 0.25x = 1.25x \times 1.20 = 1.5x \]
We know that Rashid pays Rs. 3600, so we set up the equation:
\[ 1.5x = 3600 \]
Now, we can solve for \( x \):
\[ x = \frac{3600}{1.5} = 2400 \]
Thus, the cost price of the article for Latif is Rs. 2400.