If the simple interest on a certain sum of money for 5 years is one–fifth of the sum, then the rate of interest per annum is Choose the correct answer: A) 4% B) 7% C) 6% D) 4% E) 3%
Explanation:   Let the Principal(P) be x   Then, Simple Interest(SI) = x/5   Time(T) = 5 years   Rate of interest per annum(R) = (100×SI)/PT   = (100 × (x/5)/(x × 5) = 20/5= 
<gadget id="calculator">20/5</gadget>
<output>4</output>
4%   Answer: Option 4%
<result>D</result>
If the simple interest on a certain sum of money for 5 years is one–fifth of the sum, then the rate of interest per annum is