2.c

/*
Problem 2 : Even Fibonacci Numbers  
Each new term in the Fibonacci sequence is generated by adding the previous two terms. 
By starting with 1 and 2, the first 10 terms will be : 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ... 
By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.
*/

#include <stdio.h>
#include <math.h>
int fibseq(int a, int b);
int main ()
{
    int a=1,b=2,sum=2,n=0;
    while(n<=4000000)
    {
        n=fibseq(a,b);
        printf(" %d ",n);
        if(n%2==0)
        {
            sum+=n;
        }
        a=b;
        b=n;
    }
    printf("\nSum = %d",sum);
    return 0;

}
int fibseq(int a, int b)
{
    int sum=0;
    sum=a+b;
    return sum;
}