how many simultaneous Apple accounts can be on one ipad

One. One Apple ID, one iPad. It is not a multi-user device.

You can, however, get email from more than one email account.

Actually it is possible to user diferent IDs for different purposes (one for icloud and another for the itunes stores). But only one for the specific function, and even that can get to be difficult to manage.

If you're referring to content or apps from the iTunes Store, however, you can have material from up to five iTunes Store accounts.

Regards.

THANKS, sounds like we need another Ipad