The correct option is A ₹800
Given,
Discount = 15%
S.P. of a chair = ₹680
We know that,
marked price - discount = selling price
Let, the marked price = x
∴ x−15% of x = 680
⇒x−15x100 = 680
⇒85x100 = 680
⇒x = 680×10085 = ₹800
So, the marked price of that chair is ₹800.