A sum of money amounts to Rs. 9800 after 5 years and Rs. 12005 after 8 years at the same rate of simple interest. The rate of interest per annum is?	Choose the correct choice
A) 16 %  B) 15 %  C) 12 %  D) 22 %  E) 19 %

Rationale: "s . i . for 3 years = ( 12005 - 9800 ) = rs . 2205 s . i . for 5 years = rs . 2205 / 3 * 5 = rs . 3675 . principal = ( 9800 - 3675 ) = rs . 6125 hence , rate = ( 100 * 3675 ) / ( 6125 * 5 ) = 12 % answer : c"
Answer: C