Functions and data structures - Quiz

What is the value of the temp variable at the end of the following code where k is the number of rows of mat?

temp = 0;

for (int i=0; i<k; i++) {

temp += mat[i][0];

}

What is the output of the following code?

void Op1 (int& y){

y *= 3;

cout << y << endl;

}

int main()

{

int x = 4;

Op1(x);

cout << x << endl;

return 0;

}