Student Class example to find average and grade

This is a student class example, where a Student class is written which accepts the Student Name and Marks as input. Depending on the marks, it will calculate the Average and assigns a Grade.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace StudentInfo

{

    class Program

    {

        static void Main(string[] args)

        {           

            Student stu = new Student();

            Console.Write("Enter Student's Name : ");

            stu.name = Console.ReadLine();

            Console.Write("Enter marks in subject 1 : ");

            stu.subject1marks = Convert.ToInt32(Console.ReadLine());

            Console.Write("Enter marks in subject 2 : ");

            stu.subject2marks = Convert.ToInt32(Console.ReadLine());

            Console.Write("Enter marks in subject 3 : ");

            stu.subject3marks = Convert.ToInt32(Console.ReadLine());

            Console.Write("Average : ");

            Console.Write(stu.marksAverage(stu.subject1marks, stu.subject2marks, stu.subject3marks));

            Console.Write("\nGrade : ");

            Console.WriteLine(stu.finalGrade(stu.marksAverage(stu.subject1marks, stu.subject2marks, stu.subject3marks)));

            Console.ReadLine();

        }       

    }

    class Student

    {

        public string name;

        public int subject1marks;

        public int subject2marks;

        public int subject3marks;

        public double average;

        public string grade;

        public double marksAverage(int subject1marks, int subject2marks, int subject3marks)

        {

            average = (subject1marks + subject2marks + subject3marks) / 3;           

            return(average);

        }

        public string finalGrade(double average)

        {

            if (average >= 90)

            {

                grade = "A";

            }

            else if ((average >= 80) & (average < 90))

            {

                grade = "B";

            }

            else if ((average > 70) & (average < 80))

            {

                grade = "C";

            }

            else

                grade = "Fail";

            return (grade);

        }       

    }

}

Output :