Correct Answer - Option 3 : 80
Given:
The selling price of an article = Rs. 144
Profit% = Cost price
Formula used:
Profit% = [(SP - CP)/CP] × 100
Calculation:
Let the cost price of article be Rs. x.
According to the question,
Now, profit is equal to the cost price
Profit percent = x
Profit% = [(SP - CP)/CP] × 100
x = [(144 - x)/x] × 100
⇒ x2 = 14400 - 100x
⇒ x2 + 100x - 14400 = 0
⇒ x2 + 180x - 80x - 14400 = 0
⇒ x(x + 180) - 80(x + 180) = 0
⇒ (x - 80)(x + 180) = 0
If (x - 80) = 0, then x = 80
If (x + 180) = 0, then x = -180 (Not possible)
∴ The cost price of an article is Rs. 80.