How can I activate an iPad with unknown Apple ID and password

If you are trying to activate an iPad and it is asking for a previous owners Apple ID and password, you have encountered the Activation Lock. This is a security feature that prevents thieves from setting up and using a stolen or lost iPad or iPhone. You have no alternative. You must contact the previous owner to get permission to use the device. If you cannot contact the previous owner return the device to where you bought it and demand a refund. If you found this ipad turn it into the police. You will never be able to activate the device and no one can help you do it.

Without the ID you can't activate the device.