Correct Answer - Option 3 : 80
Given:
A shopkeeper marked a price of an article at x% above the cost price and he sold it discount of 0.5x%, then he earns 8% profit.
Calculation:
According to the question,
⇒ x – 0.5x – x(0.5x)/100 = 8
⇒ 0.5x – x2/200 = 8
⇒ x2 – 100x + 1600 = 0
⇒ x2 – 80x – 20x + 1600 = 0
⇒ x(x – 80) – 20(x – 80) = 0
⇒ (x – 80)(x – 30) = 0
⇒ x = 80, 20
According to the condition,
⇒ x = 80
∴ The value of x is 80.