Error shows, " answer cannot be resolved to a variable"

Question

public class wrong {
  public static void main(String[] args) {
	  double y = 8.0;
	  double x = 10.01;
      double last = mystery(x,y);
	  y = 8.0;
	  System.out.println("x = "+  x +" and y = "+y);
	  mystery(x,y);
	  System.out.println("x = "+  x +" and y = "+ answer);
	  int z = 5;
	  System.out.println("z = "+z);
  }

  public static double mystery(double num1, double num2) {
	
   	 double answer= 867.5309;
	 return answer;
	
  }
}

Answer 1

I think it is because you should be calling the method 'mystery' rather than 'answer', the value you returned.

Answer 2

You do not call the variable "answer". Even though you returned answer from the method mystery, the value for "answer" is not being called in the main method thus making the value for answer float in "coding oblivion"