No—each group can have a different number of students in it.
Here is a start on coding the program:
import java.io.*;
class TestGroups
{
public static void main ( String[] args ) throws IOException
{
String line;
BufferedReader stdin = new BufferedReader(
new InputStreamReader( System.in ) );
int value; // the value of the current integer
// Group "A"
int sizeA; // the number of students in group "A"
int sumA = ___; // the sum of scores for group "A"
System.out.println("How many students in group A:");
line = stdin.readLine();
sizeA = Integer.parseInt( line.trim() );
int count = _______; // initialize count
while ( count < ________ )
{
System.out.println("Enter a number:");
line = stdin.readLine();
value = Integer.parseInt( line.trim() );
___________________ ; // add to the sum
___________________ ; // increment the count
}
if ( sizeA > 0 )
System.out.println( "Group A average: " + ___________________ );
else
System.out.println( "Group A has no students" );
// Group "B"
. . . . more code will go here . . . .
}
}