Exer8

#include
#include


void main()
{
clrscr();
float sum,grade,average;
int a=0;
gotoxy(17,3);textcolor(WHITE);cprintf(" G R A D I N G S Y S T E M\n");
while(grade!=-1)
{sum=sum+grade;
printf("\nEnter grade;-1 to exit:");
scanf("%f",&grade);

if(grade==-1)
{printf("\nAverage is %.2f\n",average=sum/a);}
a++;
}
if(average>=95 && average<=100.00){ printf("\n\nRated of this average: A");} else if(average>=90 && average<=94.99){ printf("\n\nRated of this average: B");} else if(average>=85 && average<=89.99){ printf("\n\nRated of this average: C");} else if(average>=80 && average<=84.99){ printf("\n\nRated of this average: D");} else if(average>=75 && average<=79.99){ printf("\n\nRated of this average: E");} else if(average<74){>