Anil invested a sum of money at a certain rate of simple interest for a period of five years. Had he invested the sum for a period of nine years for the same rate, the total intrest earned by him would have been sixty percent more than the earlier interest amount. Find the rate of interest p.a. Choose the correct option.
A) 6%
B) 9%
C) 12.5%
D) Cannot be determined
E) None of these
Let the sum be Rs.P. Let the rate of interest be R% p.a.   (P)(9)(R)/100 = [1 + 6/100][ (P)(5)(R) /100] = 1.6{5PR/100]   9PR/100 = 9PR/100 which is anyway true.   R cannot be found.   ANSWER:Cannot be determined
<result>D</result>
Anil invested a sum of money at a certain rate of simple interest for a period of five years. Had he invested the sum for a period of nine years for the same rate, the total intrest earned by him would have been sixty percent more than the earlier interest amount. Find the rate of interest p.a.