A sum of 12,500 amounts to 15,500 in 4 years at the rate of simple interest. What is the rate of interest?
Choose one:  A) 2%  B) 1%  C) 6%  D) 5%  E) 8%
C   6%   S.I. = (15500 - 12500)= 
<gadget id="calculator">(15500 - 12500)</gadget>
<output>3_000</output>
3000.   Rate= (100 x 3000)/(12500x4)% = 6%
<result>C</result>
A sum of 12,500 amounts to 15,500 in 4 years at the rate of simple interest. What is the rate of interest?