Quiz

The only way to do this would is to use a multianswer calculated question.
Are you using this for a small moodle installation i.e. one course or a large installation?
Are you using thiseas part of the grading process or as an exercise?
And which moodle version ?
At a small scale I could furnish you an experimental version of the project.

Pierre

Here is a solution
You put somewhere in the introduction text of the quiz the expression 'synchronize_calculated' and your calculated questions will use the same data number.
You need to modify the question/type/calculated/questiontype.php part that is bold, not all the function because the database calls are specific to 2.0

function create_session_and_responses(&$question, &$state, $cmoptions, $attempt) {
// Find out how many datasets are available
global $CFG, $DB;
if(!$maxnumber = (int)$DB->get_field_sql(
"SELECT MIN(a.itemcount)
FROM {question_dataset_definitions} a,
{question_datasets} b
WHERE b.question = ?
AND a.id = b.datasetdefinition", array($question->id))) {
print_error('cannotgetdsforquestion', 'question', '', $question->id);
}

// Choose a random dataset
if (!isset($cmoptions->intro) || strstr($cmoptions->intro, 'synchronize_calculated') === false ) {
$state->options->datasetitem = rand(1, $maxnumber);
}else{
if( !isset($cmoptions->synchronize_calculated)) {
$state->options->datasetitem = rand(1, $maxnumber);
$cmoptions->synchronize_calculated = $state->options->datasetitem ;
}else {
if ($cmoptions->synchronize_calculated <= $maxnumber){
$state->options->datasetitem = $cmoptions->synchronize_calculated ;
}else {
$state->options->datasetitem = rand(1, $maxnumber);
}
}
};
$state->options->dataset =
$this->pick_question_dataset($question,$state->options->datasetitem);
$state->responses = array('' => '');
return true;
}

You should create the same number of items for each datasets.
Also note that the number used is applied to all datasets private or category.
I think I will use this feature so thanks for the cue.

Pierre

See MDL-17278 which is an answer to your request.

Pierre