What is the rate percent when the simple interest on Rs.800 amount to Rs.160 in 4 Years?  Choices:  A) 5 %  B) 7 %  C) 9 %  D) 2 %  E) 4 %

Rationale: "160 = ( 180 * 4 * r ) / 100 r = 5 % answer : a"
Answer: A