How long did Adam and Eve live in the Garden of Eden? The Bible does not say. It could have been billions of years.
No, the Bible does not say directly, but it could not have been billions of years. The Bible clearly says that Adam only lived 930 years, and that Seth was born when Adam was 130 years old. It’s probably safe to assume that Seth, along with Cain and Abel who preceded him, were born after Adam and Eve were expelled from Eden, since they aren’t mentioned in the narrative of the Garden, and their conception and birth is told of immediately after the expulsion.
If Seth was born when Adam was 130 years old, after Cain killed Abel, then the expulsion probably happened at least a couple decades earlier, since Cain and Abel seem to be adults, offering their own sacrifices to God, at the time of Abel’s murder. So, there is probably a maximum of around 110 years that Adam could have spent in the Garden.