In what time a sum of money double itself at 7% per annum simple interest?  Pick:
A) 33 1/8%
B) 33 1/3%
C) 14 2/7%
D) 32 1/3%
E) 23 1/3%
P = (P*7*R)/100   R = 14 2/7%   Answer: 14 2/7%
<result>C</result>
In what time a sum of money double itself at 7% per annum simple interest?