At what rate percent of simple interest will a sum of money double itself in 12 years?  Options
A) 8 1/6 %	B) 8 1/3 %	C) 8 8/3 %	D) 8 3/3 %	E) 8 1/2 %
Let sum = x. Then, S.I. = x.   Rate = (100 * S.I.) / (P * T) = (100 * x) / (x * 12)   = 25/3 = 8 1/3 %.Answer: 8 1/3 %
<result>B</result>
At what rate percent of simple interest will a sum of money double itself in 12 years?