Final answer:
There were no cities that had only a football team.
Step-by-step explanation:
To find the number of cities that had only a football team, we need to subtract the cities that had multiple sports teams from the total number of cities with a football team.
We are given that there were 99 cities surveyed, and out of those, 27 had baseball, 25 had football, and 22 had basketball. Furthermore, 13 cities had both baseball and football, 12 had both baseball and basketball, 12 had both football and basketball, and 6 had all three sports teams.
To find the number of cities that had only a football team, we can start by subtracting the cities that had multiple teams from the total number of cities with a football team.
Out of the 25 cities with football, 13 had both baseball and football, and 12 had both football and basketball. We subtract 13 + 12 = 25 from the total number of cities with football, which gives us 25 - (13 + 12) = 25 - 25 = 0.
Therefore, there were no cities that had only a football team.