Joe invested a certain sum of money in a simple interest bond whose value grew to $260 at the end of 3 years and to $360 at the end of another 5 years. What was the rate of interest in which he invested his sum?	Choose the correct option:
A) 6%
B) 8%
C) 10%
D) 12%
E) 15%
In 5 years, the value grew $100, so the simple interest was $20 per year.   In 3 years, the total interest was 3*$20 = $60   The principal is $260 - $60 3* 20= 
<gadget id="calculator">3* 20</gadget>
<output>60</output>
$60   The principal is $260 - $60 = 200.   The interest rate is $20/$200 260 -  60= 
<gadget id="calculator">260 -  60</gadget>
<output>200</output>
200.   The interest rate is $20/$200= 10%   The answer is 10%.
<result>C</result>
Joe invested a certain sum of money in a simple interest bond whose value grew to $260 at the end of 3 years and to $360 at the end of another 5 years. What was the rate of interest in which he invested his sum?