An item was sold for Rs. 3600 at 25% discount. Its marked

C.P. of article = Rs. x (let).
According to the question,

x × 75	= 3600
100

⇒ x =	3600 × 100	= Rs. 4800
	75

Second method :
Here,S.P. = Rs. 3600
D = 25%
M.P. = ?

M.P. =	S.P. × 100
	100 − D

M.P. =	3600 × 100
	100 − 25

M.P. =	360000
	75

= M.P. = Rs. 4800