If rupee one produces rupees nine over a period of 40 years, find the rate of simple interest?	Choose the correct option.
A) 22 1/8 %  B) 22 9/2 %  C) 22 1/7 %  D) 22 1/2 %  E) 21 1/2 %
9 = (1*40*R)/100   R = 22 1/2 %   Answer:22 1/2 %
<result>D</result>
If rupee one produces rupees nine over a period of 40 years, find the rate of simple interest?