Is Greek older than Sanskrit?

NO!

Sanskrit is as old as Sanatana Dharma and is used as means for Comunication and dialogues by the Hindu Celestial Gods.

Yes, all languages are derived from sanskrit -:

Now u have to accept truth, Sanskrit is mother, father of all existing languages.

Source of this information:
https://www.quora.com/Is-Sanskrit-derived-from-Latin-or-Greek

Sanskrit is the oldest language.