A sum of Rs. 1000 amounts to Rs. 1200 in 4 years at the rate of simple interest. What is the rate of interest?  Choose the correct choice
A) 7%
B) 9%
C) 5%
D) 6%
E) 2%
S.I. = (1200 - 1000) = Rs. 200\   Rate = (100 * 200) / (1000* 4)= 
<gadget id="calculator">(100 * 200) / (1000* 4)</gadget>
<output>5</output>
5%   Answer: 5%
<result>C</result>
A sum of Rs. 1000 amounts to Rs. 1200 in 4 years at the rate of simple interest. What is the rate of interest?