Calculation:
Let the CP (Purchase Price) of the desktop be Rs.x
So, the CP of the laptop = Rs.(50000 – x)
Hence, the SP of the desktop is calculated as:
SPdesktop = [(100 + 20)/100] × x = 1.2x
Similarly, for the laptop,
SPlaptop = [(100 – 10)/100] × x = 0.9 × (50000 – x)
⇒ SPlaptop = 45000 – 0.9x
Hence, the total SP = (45000 – 0.9x) + 1.2x = 0.3x + 45000 ----(iv)
Also, the total CP = Rs.50000 ----(v)
So, from the relation for Profit%, we get:
⇒ 2 = [(0.3x + 45000 – 50000)/50000] × 100
⇒ 2 = [(0.3x – 5000)/500]
⇒ 0.3x = 6000
⇒ x = 20000
∴ The Purchase Price of the desktop is Rs. 20000
If SP = Selling Price, and CP = Cost Price. Then:
%Profit = [(SP – CP)/CP] × 100 ----(i)
If an article is sold at a Loss of a%:
SP = [(100 – a)/100] × CP ----(ii)
Similarly, if the article is sold at a Profit of a%:
SP = [(100 + a)/100] × CP ----(iii)