Letter Grade Calculater

 I write a program which calculate the letter grade.
 It is also simple program. I started to use dynamic
 memory allocation with this program. 








 Here is the code :

#include <stdio.h>
#include <stdlib.h>
void pass(double *a,int b,char *c)
{
    int i;
    double d=0;
    for(i=0;i<b;i++)
    {
        d+=a[i];
    }
    d/=(double)b;
    if(d<101&&d>89)
    *c='A';
    else if(d<90&&d>79)
    *c='B';
    else if(d<80&&d>69)
    *c='C';
    else if(d<70&&d>59)
    *c='D';
    else if(d<60&&d>0)
    *c='F';
    else
    *c='E';
}
int main()
{
    int num,i;
    double *grades;
    char note;
    printf("Enter the number of grades\n");
    scanf("%d",&num);
    grades=(double *)calloc(num,sizeof(double));
    for(i=0;i<num;i++)
    {
        printf("Enter a numeric grade between 0-100\n");
        scanf("%lf",&grades[i]);
    }
    pass(grades,num,&note);
    printf("The grade is %c\n",note);
    free(grades);
    system("PAUSE");
    return 0;
}