Boy sells a book for Rs. 540 he gets a loss of 10 %, To gain 10%, what should be the SP? Options.
A) 430 B) 450 C) 550 D) 590 E) 660

Rationale: "cost price = 540 / 90 x 100 = 600 to gain 10 % = 600 x 10 / 100 = 60 sp = cp + gain = 600 + 60 = 660 answer : e"
Answer: E