Question

The annual examination result of 50 students in a class is tabulated in a Single Dimensional Array (SDA) is as follows: 

Roll No.	Subject A	Subject B	Subject C
.....................	.....................	.....................	.....................
.....................	.....................	.....................	.....................
.....................	.....................	.....................	.....................

Write a program to read the data, calculate and display the following:

1. Average marks obtained by each student.
2. Print the roll number and the average marks of the students whose average is above 80.
3. Print the roll number and the average marks of the students whose average is below 80.

Answer 1

import java.util.Scanner;
class Q11{
public static void main(String args[])
{
Scanner sn = new Scanner(System.in);
int i;
int roll[] = new int[50]; // Change to 4 during testing
String name[] = new String[50];
double A[] = new double[50]; // subject A
double B[] = new double[50]; // subject B
double C[] = new double[50]; // subject C
double avg[] = new double[50];

for (i = 0; i < roll.length; i++)
{
System.out.print("\n\nroll number: ");
roll[i] = sn.nextInt();
System.out.print("Name: ");
name[i] = sn.next();
System.out.print("Sub. A mark: ");
A[i] = sn.nextDouble();
System.out.print("Sub. B mark: ");
B[i] = sn.nextDouble();
System.out.print("Sub. C mark: ");
C[i] = sn.nextDouble();

avg[i] = (A[i] + B[i] + C[i]) / 3;
System.out.println("Average = " + avg[i]);
}

System.out.println("\n*** AVERAGE > 80 ***");
for (i = 0; i < roll.length; i++)
{ if (avg[i] > 80)
System.out.println("Roll no: " + roll[i] + " Average: " + avg[i]);
}

System.out.println("\n*** AVERAGE <80 ***");
for (i = 0; i < roll.length; i++)
{ if (avg[i] < 80)
System.out.println("Roll no: " + roll[i] + " Average: " + avg[i]);
}
}}