At what rate percent per annum will a sum of money double in 5 years.
Choose the correct choice:
A) 20.0 %
B) 13.5 %
C) 11.5 %
D) 14.5 %
E) 21.5 %

Rationale: let principal = p , then , s . i . = p and time = 8 years rate = [ ( 100 x p ) / ( p x 5 ) ] % = 20.0 % per annum . answer : a
Answer: A