The compound interest earned on a sum for the second and the third years are $1200 and $1272 respectively. What is the rate of interest? Answers
A) 4%
B) 6%
C) 8%
D) 10%
E) 12%
1272 - 1200= 
<gadget id="calculator">1272 - 1200</gadget>
<output>72</output>
72 is the rate of interest on $1200 for one year.   The rate of interest= (100 * 72) / (1200)= 
<gadget id="calculator">(100 * 72) / (1200)</gadget>
<output>6</output>
6%   The answer is 6%.
<result>B</result>
The compound interest earned on a sum for the second and the third years are $1200 and $1272 respectively. What is the rate of interest?