Let the purchase price of the desktop be Rs \( x \).
Consequently, the purchase price of the laptop is Rs \( 50000 - x \).
The desktop is sold at a 20% profit, resulting in a selling price of:
\( \text{Selling Price of Desktop} = x + 0.2x = 1.2x \).
The laptop is sold at a 10% loss, yielding a selling price of:
\( \text{Selling Price of Laptop} = (50000-x) - 0.1(50000-x) = 0.9(50000-x) \).
An overall profit of 2% was achieved, meaning the total selling price is:
\( \text{Total Selling Price} = 50000 + 0.02 \times 50000 = 51000 \).
The governing equation is therefore:
\( 1.2x + 0.9(50000-x) = 51000 \).
Upon simplification:
\( 1.2x + 45000 - 0.9x = 51000 \)
\( 0.3x = 6000 \)
\( x = \frac{6000}{0.3} = 20000 \).
Hence, the purchase price of the desktop is Rs 20000.