California has five MLB teams (San Francisco Giants, Oakland Athletics, Los Angeles Angels, Los Angels Dodgers, San Diego Padres). There are three cities that have two baseball teams - Los Angeles (though the Angels actually play in Anaheim), New York (Yankees and Mets), and Chicago (Cubs and White Sox). Other states that have multiple teams are Texas (Texas Rangers and Houston Astros), Florida (Tampa Bay Rays and Florida Marlins), and Missouri (Kansas City Royals and St. Louis Cardinals).
Japanese teams
30 teams
yes during inter league play
not many
No one. Players are not allowed to play for two different teams in the same game in professional baseball.
Chicago
they have 162
Philadelphia Phillies
140
los angeles dodgers
Yes, they play baseball in Brazil. Of course there are no MLB teams.
Yes. Each season teams will play 15 to 18 games against teams from the other league.