Complex sentence: The expansion occurred on January 31,2010, as 10 Mega Millions members began selling Powerball tickets for their first drawing on February 3; simultaneously, 23 Powerball members began offering Mega Millions tickets for their first drawing on February 2.
Split into simpler sentences: The expansion occurred on January 31,2010, as 10 Mega Millions members began selling Powerball tickets for their first drawing on February 3. Simultaneously, 23 Powerball members began offering Mega Millions tickets for their first drawing on February 2.