Identify the number of instances and local variables present in the student class given below.

public class Student {
      public int rollNo;
      public String studentName;
      public void findGrade(int marks) {
      char grade;
      if(marks90)
      grade='A';
      else if(marks90&&marks70)
      grade='B';
     else if(marks80&&marks70)
     grade='C';
     else
        grade='D';
        System.out.prinlnt(grade);
    }
}