Question

How to use the "rand" instruction

Answer 1

Which language? For C, see this manual for details and examples.

A quick example:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main ()
{
    srand(time(NULL)); // Initialzie the random number generator with a random seed.
    int randomNumber = rand() % 100 + 1; // Generate a random number berween 100 (0..99 + 1)
    printf("The random number is: %d\n", randomNumber);
    return 0;
}