Simple interest on a certain sum of money for 4 years at 10% per annum is half the compound interest on Rs. 3000 for 3 years at 12% per annum. The sum placed on simple interest is	Choose the correct option.
A) Rs.3000 B) Rs.607.39 C) Rs.1214.78 D) Rs.1518.48 E) None
Solution   C.I.	=Rs[3000x(1+12/100)3-3000]   Rs.(3000x112/100x112/100x112/100-3000)	= Rs.1214.78.   Sum	=Rs. [607.39x100 /4x10]   = Rs.1518.48.   Answer Rs.1518.48
<result>D</result>
Simple interest on a certain sum of money for 4 years at 10% per annum is half the compound interest on Rs. 3000 for 3 years at 12% per annum. The sum placed on simple interest is