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?  Choose the correct option:
A) 16%	B) 15%	C) 12%	D) 22%	E) 19%
S.I. for 3 years = (12005 - 9800) = Rs. 2205   S.I. for 5 years = Rs. 2205/3 * 5 = Rs. 3675.   Principal = (9800 - 3675) = Rs. 6125   Hence, rate = (100 * 3675) / (6125 * 5)= 
<gadget id="calculator">(100 * 3675) / (6125 * 5)</gadget>
<output>12</output>
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?