Question

A dealer sells an article for ₹ 75 and gains as much percent as the cost price of the article. Find the cost price of the article.

Answer 1

Let the cost price of the article be x 

∴ Gain percent x% 

According to the given condition, 

₹ x + ₹ `(x/100 xx x)`

= ₹ 75 

⇒ x² + 100x = 7500

⇒ x² + 100x – 7500 = 0

⇒ x² + 150x – 5x – 7500 = 0

⇒ x (x + 150) – 50 (x + 150) = 0 

⇒ (x – 50)(x + 150) = 0 

⇒ x – 50 = 0 or x + 150 = 0

⇒ x = 50 or x = –150

∴ x = 50   ...(Cost price cannot be negative)

Hence, the cost price of the article is ₹ 50.