For some reason everytime i run my program the answer is always B. Im not sure why this is, please help!

Code://Figure out letter grade if (the_student.percentTotal>= 90) { the_student.letterGrade = 'A'; } else if ((the_student.percentTotal>= 80) || (the_student.percentTotal < 90)) { the_student.letterGrade = 'B'; } else if ((the_student.percentTotal>= 70) || (the_student.percentTotal < 80)) { the_student.letterGrade = 'C'; } else if ((the_student.percentTotal>= 60) || (the_student.percentTotal < 70)) { the_student.letterGrade = 'D'; } else if (the_student.percentTotal<60) { the_student.letterGrade = 'F'; }