The S.I. on a certain sum of money for 4 years at 12% per annum is half the C.I. on Rs. 6000 for 2 years at 15% per annum. The sum placed on S.I. is?
Choose the correct option:  A) 2019.625  B) 2017.625  C) 2013.625  D) 2015.625  E) 2011.625
C.I. = [6000 * (1 + 15/100)2 - 6000]
= (6000 * 23/20 * 23/20 - 6000) = Rs. 1935.
Sum = (967.5 * 100)/(4 * 12)
= Rs.2015.625
Answer:2015.625
<result>D</result>
The S.I. on a certain sum of money for 4 years at 12% per annum is half the C.I. on Rs. 6000 for 2 years at 15% per annum. The sum placed on S.I. is?