In what time a sum of money double itself at 7% per annum simple interest?  Options:
A) 33 1/8%	B) 33 1/3%	C) 14 2/7%	D) 33 4/3%	E) 73 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?