Kabir buys an article with 25% discount on its marked price. He makes a profit of 10 % by selling it at Rs. 660. The marked price is :

A. Rs. 600
B. Rs. 700
C. Rs. 800
D. Rs. 685
Explanation:
Original price be Rs. X
C.P = (X – 25% of X) = 3X/4
S.P = (3X/4 + 10% of 3X/4) = 33X/40
33X/40 = 660
=> X = 800