public static double calculatePassingExamScore(double semesterGrade)
{
	if((semesterGrade *4 + 100)/5 < 59.5) return -1; //can't pass
	if(semesterGrade * 4 /5 >=59.5) return 0;  //you will pass no matter what
	return 500 *.595 - 4 * semesterGrade;
	
	//  4/5 of grade is semesterGrade
	//  1/5 is ExamScore
}