Neither do they separately exist or co exist. The word exist it self means utpad-vyay-dhrovyatmak. One who understands the word exist will not have the question about separate/independent existence.
Sayyamji has made a good attempt to explain
To further and clearly understand the word exist… read it this way …
A substance has attributes through which it fuctions and it expresses its efficiency through its modification. Oneness of it all is call exist.