A sum of money triples itself in ten years at simple interest. Find the rate of interest?	Choices:
A) 12 1/2 % p.a.
B) 14 1/2 % p.a.
C) 20 % p.a.
D) 22 % p.a.
E) 25 % p.a.
Let the pricipal be Rs. x, then amount = 3x(where R = rate of interest) =&gt; Interest = 3x - x = Rs. 2x   R = (100 * 2x)/(x * 10) = 20 %   ANSWER:20 % p.a.
<result>C</result>
A sum of money triples itself in ten years at simple interest. Find the rate of interest?