Which of the following statement is correct about the program given below?

#include<iostream.h>
#include<string.h>
#include<malloc.h>
class CuriousTabString
{
    char txtName[20]; 
    public:
    CuriousTabString(char *txtTemp = NULL)
    {
        if(txtTemp != NULL)
        strcpy(txtName, txtTemp);
    }
    void Display(void)
    {
        cout<<txtName;
    }
};
int main()
{
    char *txtName = (char*)malloc(10);
    strcpy(txtName, "CuriousTab");
    *txtName = 48;
    CuriousTabString objTemp(txtName);
    cout<< sizeof(txtName);
    return 0; 
}

#include<iostream.h> 
int main()
{
    float Amount;
    float Calculate(float P = 5.0, int N = 2, float R = 2.0);
    Amount = Calculate(); 
    cout<< Amount << endl; 
    return 0;
}

float Calculate(float P, int N, float R)
{
    int Year = 1;
    float Sum = 1 ;
    Sum = Sum * (1 + P * ++N * R);
    Year =  (int)(Year + Sum);
    return Year; 
}

#include<iostream.h> 
class CuriousTab
{
    int x; 
    public:
    CuriousTab(int xx, float yy)
    {
        cout<< char(yy);
    } 
}; 
int main()
{
    CuriousTab *p = new CuriousTab(35, 99.50f);
    return 0; 
}