A sum of money amounts to Rs. 9800 after 5 years and Rs. 12005 after 8 years at the same rate of simple interest. The rate of interest per annum is:	Options
A) 5%
B) 8%
C) 12%
D) 15%
E) 18%
S.I. for 3 years = Rs. (12005 - 9800) = Rs. 2205.   S.I. for 5 years = Rs.(2205x5)/3= Rs. 3675   Principal = Rs. (9800 - 3675) = Rs. 6125.   Hence, rate = (100 x 3675)/(6125x5)	%	= 12% ANSWER :12%
<result>C</result>
A sum of money amounts to Rs. 9800 after 5 years and Rs. 12005 after 8 years at the same rate of simple interest. The rate of interest per annum is: