C# Application to act as a Magic 8 ball

Random rnd = new Random();

if((rnd.Next() & 1) == 0)
{
    // Yes ...
}
else
{
   // No
}

This works by checking if the lowest bit is not set (integer is even) but you could also check if bit is set ( == 1 which amounts to odd).

Another way to go is % (modulo operator) which gives the remainder.
x % n gives the remainder of the division of x by n: e.g X = 6 N = 3
6 % 3 == 0

This is very usefull if you need more than the 2 options "yes" and "no".
For example:

0 == "Yes"
1 == "No"
2 == "Ask again later"
3 == "Not very likely"

int numberOfChoices = 4;
Random rnd = new Random();
switch(rnd % numberOfChoices)
{
    case 0:
        //"Yes" stuff goes here
        break;
    case 1:
        //"No" stuff goes here
        break;
    case 2:
        //"Ask again later" stuff goes here
        break;
    case 3:
        //"Not very likely" stuff goes here
        break;

}

Cheers

Manfred