You can learn what version of PHP is running on your server by running a phpinfo file. You can make your own phpinfo file by entering only the following (no blank lines) into a text file:
<?php phpinfo(); ?>
Now, save the file as "phpinfo.php", upload it to your server, and access it via your browser. There's tons of useful information there, including your server's PHP version.
I don't work here. I'm just your typical support forum volunteer.