Final answer:
You bought airplane tickets in advance but the flight was overbooked and you were not allowed to board the flight due to overbooking.
Step-by-step explanation:
Based on the given information, it appears that you had bought airplane tickets in advance, but the flight was overbooked and you were not allowed to board the flight.
The situation can be better understood by referring to the diagram in Figure 2.9 which shows a detailed record of an airplane passenger heading toward the back of the plane.
It is important to note that in such cases, airlines typically offer compensation or alternative arrangements to accommodate passengers who are unable to board a flight due to overbooking.