To gain 25% after allowing a discount of 10%, the shopkeeper must mark the price of the article which costs him ₹360 as:
₹ 500
Let the M.P be ₹x
Gain = 25%
C.P of article = ₹360
S.P=100 + gain%100 × C.P
S.P=125100 × 360
= ₹450
Discount = 10%
S.P=100 − discount%100 × M.P
450=90x100
x= 450 × 100 90
x=₹500
So, the shopkeeper must mark the price of the article at ₹500