mysql_num_rows, resource id #

In my code below, I am trying to verify that the query is selecting data from both rows of my answers table.  I have run the query on my MySQL CLI and getting answers from both rows, but running this script I get $rows = 0.  I can't figure out why its not returning 2 for the number of rows.  It is not giving me any error msgs such as cannot connect.  

Also can tell me where I can find documentation on resource id #, such as resource(5)?
<?PHP
DEFINE ("host","localhost");
DEFINE ("user","root");
DEFINE ("password","pasword");
DEFINE ("database","questions");

$connection=mysql_connect(host,user,password) or die ('Could not connect' . mysql_error() );

$dbConnect=mysql_select_db('questions',$connection);
if (!$dbConnect) {die ('Could not connect to database' . mysql_error() );}

$result = mysql_query("Select answer from answers where studentID='A123456789'") or die(mysql_error());
$rows = mysql_num_rows($result);
echo $rows;


?>