In a push for better wages, fast-food workers staged strikes and held rallies in some 200 cities across the United States on Monday. The latest round of protests organized by the Service Employees International Union was intended to help low-wage workers shine a spotlight on economic disparities and to gain support for legislation to raise the federal minimum wage of $7.25. That comes to about $15,000 a year for full-time work. Sen. Bernie Sanders is a cosponsor of a bill to raise the minimum wage to at least 10.10 an hour.