Q: Cable

Welcome to Apple Support Communities

It depends. Open System Profiler or System Information (in /Applications/Utilities) and tell us which the model identifier is. With its model identifier, we can know which MacBook Pro you have and give you the possible adapters, because a 2007 and a 2009 MacBook Pro don't have the same ports.

The most common connectors on a TV to connect your Mac are HDMI, DVI or VGA. Check which ports you have on the TV and tell us them. If you can use HDMI, use it

You shouldn't post the serial number.

As you have a Mid 2012 MacBook Pro, you have to get a Mini DisplayPort adapter (to HDMI, DVI or VGA, depending on the ports your TV has) and the cable. If you are going to use HDMI > http://support.apple.com/kb/HT4241?viewlocale=en_US&locale=en_US

The serial number gives people information about your MacBook and they can even register it with their Apple ID if you didn't register it