At what rate percent per annum will the simple interest on a sum of money be 4/5 of the amount in 10 years? Options
A) 4%
B) 7%
C) 8%
D) 3%
E) 1%
Let sum = x. Then, S.I. =4x/5, Time   = 10 years.   Rate = (100 * 4x) / (x * 5 * 10)   = 8%   Answer: 8%
<result>C</result>
At what rate percent per annum will the simple interest on a sum of money be 4/5 of the amount in 10 years?