Exactly the same number of transactions as it does now.
...
how is it possible? Only 3 miners will mean a lot less block, and less block will be less transactions. How can be no difference?
You really need to do some research and find out how Bitcoin works. For someone with a 2013 Hero account, I'm very surprised you don't know the basics. The difficulty of finding a block is calculated to always keep block generation constant at 6 blocks per hour. If there is less hashpower on the network then difficulty will be reduced and the same number of blocks will be found. That is just the opposite of what happens everytime miners add more hashpower, the difficulty goes up and the same number of blocks are found.
Edit:
Trust summary for asdlolciterquit
This user's password was reset recently.
This user's email address was changed recently.
Oh, you bought the account that explains it.