Simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs. 4000 for 2 years at 10% per annum. The sum placed on simple interest is  Pick one: A) Rs.1550 B) Rs.1650 C) Rs.1750 D) Rs.2000 E) None
Solution   C.I.	=Rs[4000x(1+10/100)²-4000]   Rs.(4000x11/10x11/10-4000)	= Rs.940.   Sum	=Rs. [420x100 /3x8]   = Rs.1750.   Answer Rs.1750
<result>C</result>
Simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs. 4000 for 2 years at 10% per annum. The sum placed on simple interest is