The formula for Future Value is FV = P (1 + r)t
where P = principal, r = rate, and t = time
in this case, we have only an idea, namely that some Principal invested at an unknown rate will have of FV of twice the Principal in 5 years.
so we must arbitrarily select a Future Value and a Principal, so I will select FV = $2000, and P = $1000
our formula becomes $2000 = $1000( 1 + r)5
2 = (1 + r)5
we then take the 5th root of 2, which is 1.1487 to get 1.1487 = 1 + r
solving, r = 0.1487 = 14.87%
