Which of these situations describe an equilibrium, and which does not? If not, what would an equilibrium look like? Remember that the definition of equilibrium means, in part, that there is no incentive or push/pull to change from the current described state.

Many people regularly commute from the suburbs to the downtown area of a local city. Due to traffic congestion, the trip takes 30 minutes when you travel by highway, and15 when you go by side streets.

There are 2 gas stations at the intersection of Main and Vine. One charges $3.75 for regular and the other charges $3.25. Customers can get gas immediately at the first station, but must wait in long lines at the second.

Every student who enrolls in econ principles must also attend a weekly tutorial. This semester, 2 sections are offered, which meet at the same time, in adjoining classrooms and are taught by equally competent and liked instructors. Section A is overcrowded with people sitting on the floor and unable to see the board and Section B has many empty seats.