A watch was sold at a loss of 10%. If it was sold for Rs.500 more, there would have been a gain of 10%. What is the cost price?  Choose the correct choice:
A) 1000  B) 2998  C) 2500  D) 2788  E) 2991

Rationale: "90 % 110 % - - - - - - - - 20 % - - - - 500 100 % - - - - ? = > rs . 2500 answer : c"
Answer: C