Correct Answer - Option 3 :

\(8\frac{4}{7}\)
**Given:**

CP = Rs. 720

MP = Rs. 900

**Concept used:**

SP = MP × (100 - discount)/100

SP = CP × (100 + profit)/100

**Calculation:**

According to the question,

900 × (100 - x)/100 = 720 × (100 + 5x/3)/100

⇒ 900 × (100 - x) = 720 × (100 + 5x/3)

⇒ 90000 - 900x = 72000 + 1200x

⇒ 90000 - 900x = 72000 + 1200x

⇒ 2100x = 18000

⇒ x = 18000/2100

⇒ x = 60/7

⇒ x = \(8\frac{4}{7}\)

**∴ The vale of x is \(8\frac{4}{7}\)**