A sum of 725 is lent in the beginning of a year at a certain rate of interest. After 8 months, a sum of 362.50 more is lent but at the rate twice the former. At the end of the year, 33.50 is earned as interest from both the loans. What was the original rate of interest?	Choose the correct answer.
A) 3.6%	B) 4.5%	C) 5%	D) 3.46%	E) None of these
Let the original rate be R%. Then, new rate = (2R)%   ∴ (725×R×1/100)+(362.50×2R×1/100×3)=33.50   ⇒ (2175 + 725)R = 33.50 × 100 × 3 = 10050   ⇒ R = 10050⁄2900 = 3.46%   Answer 3.46%
<result>D</result>
A sum of 725 is lent in the beginning of a year at a certain rate of interest. After 8 months, a sum of 362.50 more is lent but at the rate twice the former. At the end of the year, 33.50 is earned as interest from both the loans. What was the original rate of interest?