Library Functions - General Questions

What will be the output of the program?

#include <stdio.h>
#include <math.h>

int main(void) {
    printf("%.0f\n", pow(2, 10));
    return 0;
}

What will be the output of the program?

#include <stdio.h>
#include <ctype.h>

int main(void) {
    printf("%d\n", isdigit('7') != 0);
    return 0;
}

What will be the output of the program?

#include <stdio.h>
#include <string.h>

int main(void) {
    char s[10];
    memset(s, '*', 3);
    s[3] = '\0';
    printf("%s\n", s);
    return 0;
}

What will be the output of the program?

#include <stdio.h>
#include <string.h>

int main(void) {
    char s[] = "hello world";
    printf("%s\n", strchr(s, 'w'));
    return 0;
}

Which function returns a pseudo-random integer?