A sum was put at simple interest at certain rate for 3 years. Had it been put at 1% higher rate it would have fetched Rs. 78 more. The sum is: A. Rs. 2,400 B. Rs. 2,100 C. Rs. 2,200 D.Rs. 2,480 Choose one:  A) 2000  B) 2600  C) 2200  D) 2300  E) 2400

Rationale: "1 percent for 3 years = 78 1 percent for 1 year = 26 = > 100 percent = 2600 answer : b"
Answer: B