Include “required questions” in a random selection

Question

I\'m selecting a set of random questions without any duplicates using the following:

Answer 1

The Question doesn't state it, but all suggests this is an Advanced Custom Fields set up using the Repeater Add-on.

In that case, this is the test configuration I've done:

Note that here I'm using $repeater_row['title'] instead of the OP's $repeater_row['question']. Also, I removed the answer_options part. See comments for details:

// Get fields
$amount = get_field( 'select_number_of_questions' );
$repeater = get_field( 'step_by_step_test' );

// Auxiliary arrays to separate fields by Field Name
$not_enabled = array();
$enabled = array();

// Separate
foreach( $repeater as $field )
{
    if( 'no' == $field['enabled'] )
        $not_enabled[] = $field;
    else
        $enabled[] = $field;
}

// Discount the enabled from the the total amount
$amount = (int)$amount - count( $enabled );

// Shuffle before slicing
shuffle( $not_enabled );
$repeater_limit = array_slice( $not_enabled, 0, $amount );

// Add enabled fields and shuffle again
$final_array = array_merge( $repeater_limit, $enabled ); 
shuffle( $final_array );

foreach( $final_array as $repeater_row ) {
    echo "
" . $repeater_row['title'] . "
";
}