13.6

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

#include <stdio.h>
#include <string.h>

#define MAX_BALL 5

struct student {
  char name[256];
  char surname[256];
  int ball[5];
};

void averagePrint(struct student *students);
void Print(struct student *students);
int main() {
  struct student persons[2];
  int n = 2, i;

  for (i=0; i<n; i++) {
    printf("Please enter the name and surname of the person #%d: ", i+1);
    scanf("%s %s", persons[i].name, persons[i].surname);
        for (int j=0; j<5; j++)
            persons[i].ball[j] = 40+rand()%100;
  }
    Print(persons);
    printf("\n");

    averagePrint(persons);

  return 0;
}
void Print(struct student *students)
{
    int n = 2;
    for (int i =0; i<n; i++) {
        printf("Name: %s. SurName: %s. Balls: ", students[i].name, students[i].surname);

        for (int j=0; j<MAX_BALL; j++)
            printf("%d\t", students[i].ball[j]);
        printf("\n");
  }

}

void averagePrint(struct student *students)
{
    int n = 2;
    float sum = 0;
    float arrAverage[2];
    for (int i=0; i<n; i++) {
        sum = 0;
        for (int j=0; j<MAX_BALL; j++)
            sum += students[i].ball[j];
        arrAverage[i] = sum / MAX_BALL;
  }
    for (int i=0; i<n; i++) {
        printf("Name: %s. SurName: %s. Average: ", students[i].name, students[i].surname);

            printf("%f\t", arrAverage[i]);
        printf("\n");
  }
  float total = 0;
    for (int i=0; i<n; i++) {
        total += arrAverage[i];

  }
    printf("\n Average group: %f", total / 2);


}