[Vince]

pawn Код:

enum quiz {
    question[64],
    correctAnswer[64],
    wrongAnswer1[64],
    wrongAnswer2[64],
    wrongAnswer3[64],
};

new quizQuestions[][quiz] = {
   {"How many apples?", "10", "5", "15", "20"},
   // etc.
};

pawn Код:

new SelectedQuestions[20] = {-1, ...}, rand;

for(new i; i < sizeof(SelectedQuestions); i++)
{
    do rand = random(sizeof(quizQuestions));
    while(inArray(rand, SelectedQuestions)); 

    SelectedQuestions[i] = rand;
}

pawn Код:

stock inArray(value, const array[], size = sizeof(array))
{
    for(new i; i < size; i++)
        if(array[i] == value) return true;

    return false;
}

There's much more to it, but this should give you an idea.