A certain sum is invested at simple interest at 18% p.a. for two years instead of investing at 12% p.a. for the same time period. Therefore the interest received is more by Rs. 300. Find the sum?
Answers:
A) 7000
B) 2500
C) 2778
D) 2800
E) 2791

Rationale: "let the sum be rs . x . ( x * 18 * 2 ) / 100 - ( x * 12 * 2 ) / 100 = 300 = > 36 x / 100 - 24 x / 100 = 300 = > 12 x / 100 = 300 = > x = 2500 . answer : b"
Answer: B