A sum was put a simple interest at a certain rate for 3 years. Had it been put at 3% higher rate, it would have fetched Rs. 90 more. The sum is:  Answers:
A) s . 750 B) s . 900 C) s . 1000 D) s . 1200 E) s . 1500

Rationale: "explanation : let the sub be rs . x and the initial rate be r % . then x ã — ( r + 3 ) ã — 3 / 100 â ˆ ’ x ã — r ã — 3 / 100 = 90 â ‡ ’ x ã — 3 ã — 3 / 100 = 90 â ‡ ’ x ã — 3 / 100 = 30 â ‡ ’ 3 x = 3000 â ‡ ’ x = 1000 answer : option c"
Answer: C