If the simple interest on a sum of money at 5% per annum for 3 years is Rs.1200, find the compound interest on the same sum for the same period at the same rate.
Choose the correct choice from the following answers:  A) 1251  B) 1261  C) 1271  D) 1281  E) None
Solution   Clearly, Rate	= 5% p.a.   Time	= 3 years   S.I	=Rs.1200.   So,Principal	=Rs.(100 x 1200/3x5)   =Rs.8000.   Amount	=Rs.[8000 x (1+5/100)³]   =Rs(8000x21/20x21/20x21/20)   = Rs.9261   C.I	=Rs.(9261-8000)   =Rs.1261.   Answer 1261
<result>B</result>
If the simple interest on a sum of money at 5% per annum for 3 years is Rs.1200, find the compound interest on the same sum for the same period at the same rate.