Braun invested a certain sum of money at 8% p.a. simple interest for 'n' years. At the end of 'n' years, Braun got back 4 times his original investment. What is the value of n?
Choose the correct choice from the following answers:
A) 50 years B) 25 years C) 12 years 6 months D) 37 years 6 months E) 40 years
Explanatory Answer   Let us say Braun invested $100.   Then, at the end of 'n' years he would have got back $400.   Therefore, the Simple Interest earned = 400 - 100= 
<gadget id="calculator">400 - 100</gadget>
<output>300</output>
$300.   We know that Simple Interest= (Principal * number of years * rate of interest) / 100   Substituting the values in the above equation we get 300 = (100 * n * 8) / 100   Or 8n = 300   Or n = 37.5 years.   choice is (37 years 6 months)
<result>D</result>
Braun invested a certain sum of money at 8% p.a. simple interest for 'n' years. At the end of 'n' years, Braun got back 4 times his original investment. What is the value of n?