A person got Rs.40 more when he invested a certain sum at compound interest instead of simple interest for two years at 10% p.a. Find the sum?  Choose the correct choice from the following choices:
A) 7500  B) 4000  C) 5000  D) 4500  E) 2671
P = (d * 1002) / R2   =&gt; (40 * 100 * 100) / 10 * 10 = Rs.4000   Answer:4000
<result>B</result>
A person got Rs.40 more when he invested a certain sum at compound interest instead of simple interest for two years at 10% p.a. Find the sum?