If the simple interest on a certain sum of money for 6 years is one–fifth of the sum, then the rate of interest per annum is  Choose the correct choice from the following
A) 3.3%
B) 7.2%
C) 6.1%
D) 5.0%
E) 3.1%
Explanation:   Let the Principal(P) be x   Then, Simple Interest(SI) = x/5   Time(T) = 6 years   Rate of interest per annum(R) = (100×SI)/PT   = (100 × (x/5)/(x × 6) = 20/6 = 3.3%   3.3%nswer: Option 3.3%
<result>A</result>
If the simple interest on a certain sum of money for 6 years is one–fifth of the sum, then the rate of interest per annum is