At what rate percent per annum will the simple interest on a sum of money be 2/5 of the amount in 10 years?  Answers:  A) 5%  B) 4%  C) 2%  D) 6%  E) 7%
Let sum = x. Then, S.I. = 2x/5, Time = 20 years.   Rate = (100 * 2x) / (x * 5 * 20) = 2%   ANSWER:2%
<result>C</result>
At what rate percent per annum will the simple interest on a sum of money be 2/5 of the amount in 10 years?