The simple interest on a certain sum of money for 2 years at 10% per annum is half the compound interest on $100 for 2 years at 5% per annum. The sum placed on simple interest is ?	Options:  A) $602.5  B) $625.8  C) $710.6  D) $745  E) $790.3
C.I. = 100* (1 + 5/100)^2 - 100 = 100* 21/20 * 21/20 -100 = $120.5   Sum = 120.5*100/2*10 = $602.5   $602.5nswer is $602.5
<result>A</result>
The simple interest on a certain sum of money for 2 years at 10% per annum is half the compound interest on $100 for 2 years at 5% per annum. The sum placed on simple interest is ?