Peter invested a certain sum of money in a simple interest bond whose value grew to $300 at the end of 3 years and further to $400 at the end of another 5 years. What was the rate of interest in which he invested his sum?	Choose the correct answer:
A) 12% B) 12.5% C) 6.67% D) 6.25% E) 8.33%
Answer   Initial amount invested = $ X   Amount at the end of year 3 = $ 300   Amount at the end of year 8 (another 5 years) = $ 400   Therefore, the interest earned for the 5 year period between the 3rd year and 8th year = $400 - $300 = $100   As the simple interest earned for a period of 5 years is $ 100, interest earned per year 400 -  300= 
<gadget id="calculator">400 -  300</gadget>
<output>100</output>
$100   As the simple interest earned for a period of 5 years is $ 100, interest earned per year= $20.   Therefore, interest earned for 3 years = 3 * 20= 
<gadget id="calculator">3 * 20</gadget>
<output>60</output>
$ 60.   Hence, initial amount invested X= Amount after 3 years - interest for 3 years   = 300 - 60= 
<gadget id="calculator">300 - 60</gadget>
<output>240</output>
$ 240.   Rate of interest= (interest per year/principal)*100 = 20/240*100 = 8.33%   choice is (8.33%)
<result>E</result>
Peter invested a certain sum of money in a simple interest bond whose value grew to $300 at the end of 3 years and further to $400 at the end of another 5 years. What was the rate of interest in which he invested his sum?