A man gets a simple interest of Rs.400 on a certain principal at the rate of 5% p.a in two years. Find the compound interest the man will get on twice the principal in two years at the same rate.
Choose the correct choice from the following choices:
A) Rs.500 B) Rs.250 C) Rs.205 D) Rs.5062.50 E) None of these.
Let the principal be Rs.P   S.I at 5% p.a in 8 years on Rs.P = Rs.400   (P)(8)(5)/100 = 400   P = 1000   Rs.205.I on Rs.2P i.e., Rs.2000 at 5% p.a in two years   =2000{ [1 + 5/100]2 - 1} = 2000{ 212 - 202 /202}   = Rs.205   ANSWER:Rs.205
<result>C</result>
A man gets a simple interest of Rs.400 on a certain principal at the rate of 5% p.a in two years. Find the compound interest the man will get on twice the principal in two years at the same rate.