Getting average using array and functions

In PHP here is the solution. Since language is not mentioned:

 $grade = [1.25, 3.0, 1.0];
 $unit = [3, 3, 3];
 $count = 0;

 foreach($grade as $key => $val){
   $count += $val * $unit[$key];
 }

 $divide = $count/array_sum($unit);

 print_r($divide);

Here in C. I don't know much about C but hope it helps.

#include <stdio.h>

float grade[] = {1.25, 3.0, 1.0};
float units[] = {3, 3, 3};
float sum = 0.0;
float count = 0.0;
int i = 0;
float division = 0;

int main()
   {
   for(i = 0; i < sizeof(grade)/sizeof(grade[0]); ++i){
      count += grade[i] * units[i];
      sum += units[i];
   }

   division = count / sum; 
   printf("%f",division);

   return 0;
}