#include <stdio.h>
#define LEN 5

/* the definition of assignment */
typedef struct {
  int mark;
  int max_mark;
  double weight;
} assignment;

int main ( void ) {
  assignment marks[LEN];
  double sum=0;
  int i;

  /* put some values in the assignments */
  marks[0].mark = 16;
  marks[0].max_mark = 20;
  marks[0].weight = 0.05;
  marks[1].mark = 18;
  marks[1].max_mark = 25;
  marks[1].weight = 0.05;
  marks[2].mark = 14;
  marks[2].max_mark = 15;
  marks[2].weight = 0.20;
  marks[3].mark = 47;
  marks[3].max_mark = 55;
  marks[3].weight = 0.20;
  marks[4].mark = 23;
  marks[4].max_mark = 25;
  marks[4].weight = 0.50;

  /* calculate the weighted average */
  for(i=0; i<LEN; i++) {
    sum += marks[i].weight * marks[i].mark / marks[i].max_mark;
  }

  printf("The average is %.2g.\n", sum);

  return 0;
}