By selling an article at Rs.900, a shopkeeper makes a profit of 25%. At what price should he sell the article so as to make a loss of 25%?  Choose the correct answer:
A) s . 600
B) s . 480
C) s . 500
D) s . 540
E) s . 550

Rationale: "sp = 900 profit = 25 % cp = ( sp ) * [ 100 / ( 100 + p ) ] = 900 * [ 100 / 125 ] = 720 loss = 25 % = 25 % of 720 = rs . 180 sp = cp - loss = 720 - 180 = rs . 540 answer : d"
Answer: D