display one array randomly on other array

i have some problem, I need to display one array randomly on other array For example : i need to display $advertises on $abc but there are display many more post

$args =array( 'post_type' => 'post',

    'meta_query' => 
    array(
        'relation'=>'OR',
         array(
          'key'  => 'to_event_date',
          'value' => date('Y/m/d'),
          'type'  => 'date',
          'compare'=>'>=',
            ),
        'relation'=>'OR',
         array(
          'key'  => 'to_event_date',
          'value' => '',
          'compare'=>'=',
          )
     )
 );

$test = query_posts( $args );

$advertise1 = array( 'posts_per_page' => 1,

                'order' => 'DESC',
                'post_type' => 'advertise',
                'post_status' => 'publish',

                'suppress_filters' => true);



    $advertises=get_posts($advertise1);

    $rand_position=rand(0,2);


    foreach($advertises as $mpost){
     $advertise=$mpost;

    }
        array_splice($test, $rand_position, 0, $advertise);

somebody help me?