At what rate percent per annum will the simple interest on a sum of money be 2/5 of the amount in 10 years?  Choose the correct choice
A) 4 %
B) 74 %
C) 64 %
D) 74 %
E) 94 %

Rationale: let sum = x . then , s . i . = 2 x / 5 , time = 10 years . rate = ( 100 * 2 x ) / ( x * 5 * 10 ) = 4 % answer : a
Answer: A