public double getCorrectPercentage(long incorrect, long correct) {
  

        if (correct < 0) {  
 	System.out.println("Invalid number of correct answers");
 	return -1;
}
        if (correct > 81) {  
 	System.out.println("Invalid number of correct answers");
 	return -1;
}
        if (incorrect < 0) {
 	System.out.println("Invalid number of incorrect answers");
 	return -1;
}        
        if (incorrect > 81) {  
 	System.out.println("Invalid number of correct answers");
 	return -1;
}	 
        double totalChoices = correct + incorrect;
   
        if (totalChoices == 0) {
        return 0;
        
}
        double completePercent = (correct / totalChoices) *100;
  
        return completePercent;
        

}