A 16GB ipod can hold 3,600 songs
8
It depends how big the song is, it also depends how much other stuff is on it, like games and other apps, they take up more than a song... Hope this helps :)
A 16GB flash drive can hold 4x as many files as a 4GB flash drive. I would recommend a 16GB.
About 4000 songs
It depends on how many gigabites you get. You can have 8GB or 16GB.
About 7000000
around 50.
About 20,000
8,000
3050 times
The FAQ section for the Kobo Arc says the 16gb Kobo can hold 14,000 books