Function gives me a wrong answer - c

Question

I'm new to C. I've been tasked to run a program that calculates the percentage of students that passed an exam,based on N grade inputs.I don't really understand how functions work in though.This is what I came up with
#include <stdio.h>
#define MAX_N 300
main()
{
int N,grade,i;
float success(N)
{
float sum=0.0;
for (i=0;i<N;i++) {
if (grade>=5) {
sum+=1;
}
float success=sum/N;
return(success);
}
}
printf("How many students? ");
scanf("%d",&N);
printf("Enter grades(0-10) of %d students ",N);
for (i=0;i<N;i++){
scanf("%d",&grade);
}
printf("%f percent of students have passed the exam ",success(N);
return(0);
}
It looks like it should work, however I always get the wrong result.It is stuck on displaying 0.2 or 0.25 for any input I give.Can somebody help?

Answer 1

The problem is that in grade only the last entered data is being stored. Make grade as an array so that all data can be stored.

Answer 2

I guess you are taking multiple value for grade and not taking array for it.
grade should be an array and in loop scanf("%d",&grade[i]); should be implement.

Answer 3

grade should be an array of N integers so that each and every value is stored. You also forgot to multiply success by 100 to get the percentage.
I think I fixed the code:
#include <stdio.h>
#define MAX_N 300
float success(int grade[],int N)
{int i;
float sum=0.0;
for (i=0;i<N;i++) {
if (grade[i]>=5) {
sum+=1;
}
}
float success=sum/N;
return(success*100);
}
int main(){
int N, i;
printf("How many students? ");
scanf("%d",&N);
int grade[N];
printf("Enter grades(0-10) of %d students ",N);
for(i=0;i<N;i++){
scanf("%d", &grade[i]);
}
printf("%f percent of students have passed the exam ", success(grade, N));
return(0);
}

Answer 4

I think you should examine the code I wrote. A little bad code. But it can help.
#include <stdio.h>
int students_success(int *);
int main() {
int n;
printf("How many students?\n");
scanf("%d", &n);
printf("Enter grades(0-10) of %d students\n", n);
int grade;
int pass_std = 0;
for(int i = 0; i < n; ++i) {
scanf("%d", &grade);
pass_std = students_success(&grade);
}
printf("%.2f percent of students have passed exam.\n", (double)pass_std / n);
}
int students_success(int *grade) {
static int pass_std = 0;
if(4 < *grade) {
++pass_std;
}
return pass_std;
}