what is rate of interest if principal.amount be 400,simple interest 80 and time 2year.  Choose the correct choice from the following
A) 10 B) 12.5 C) 25 D) 12 E) 14.5
s.i=(p*r*t)/100   80=800r/100   r=80/8= 
<gadget id="calculator">80/8</gadget>
<output>10</output>
10%   answer 10
<result>A</result>
what is rate of interest if principal.amount be 400,simple interest 80 and time 2year.