4-2
#include<stdio.h> int main(void) { int count,num; double grade,total; num=0; total=0; count=0; printf("Enter grades:"); scanf("%lf",&grade); while(grade>=0){ total=total+grade; num++; if(grade<60) count++; scanf("%lf",&grade); } if(num!=0){ printf("Grade average is%.2f\n",total/num); printf("Number of failures is%d\n",count); } else printf("Grade average is 0\n"); return 0; }