A certain sum is invested at simple interest at 15% 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. 720. Find the sum?	Answers
A) s . 7000	B) s . 9000	C) s . 14000	D) s . 12000	E) s . 27000

Rationale: "let the sum be rs . x . ( x * 15 * 2 ) / 100 - ( x * 12 * 2 ) / 100 = 720 = > 30 x / 100 - 24 x / 100 = 720 = > 6 x / 100 = 720 = > x = 12000 . answer : d"
Answer: D