fails:Kernel.Rational when passed a String converts the String to a Rational using the same method as String#to_r
fails:Kernel.Rational when passed a String scales the Rational value of the first argument by the Rational value of the second
fails:Kernel.Rational when passed a String does not use the same method as Float#to_r
fails:Kernel.Rational when passed a String when passed a Complex returns a Rational from the real part if the imaginary part is 0
fails:Kernel.Rational when passed a String when passed a Complex raises a RangeError if the imaginary part is not 0
