Display Grading of 100 Student

/*Display Grading of 100 Student*/

#include<stdio.h>
#include<conio.h>
void main()
{

clrscr();
int roll[100],mark[10],sum=0;
float avg;
printf("Result of 100 students of 10 subjects=\n");
printf("\n\n");
for(int i=1;i<=100;i++)
{
printf9"Enter Roll no");
scanf("%d",&roll[i]);
printf("Enter marks of 10 Subjects for Roll no=%d\n:",roll[i]);
for(int j=1;j<=10;j++)
{
scanf("%d",&mark[j]);
sum=sum+mark[ij];
avg=sum/10.0;
}
printf("Average marks=%.2f",avg);
if(avg>=90)
printf("(Grading=A+)\n\n");
else
if(avg>=80&&ave<90)
printf("(Grading=A)\n\n");
else
if(avg>=70&&ave<80)
printf(("(Grading=B+)\n\n");
else
if(avg>=60&&ave<70)
printf("(Grading=B)\n\n");
else
if(avg>=50&&ave<60)
printf("(Grading=C+)\n\n");
else
if(avg>=40&&ave<50)
printf("(Grading=C)\n\n");
else
printf("**FAIL**");
}
getch();
}

Input 100 student 10 subject mark and get their Result sheet.