You are going for a train ride across the country with your dumb friend Emil. Since you do not trust Emil’s faculties, you choose to buy the two tickets yourself. The D-day comes but, unfortunately, you are very late. You happen to be the last passenger not yet seated in the train.
You are exhausted, but your troubles aren’t far from being over. You hear that some guy named Emil came very early this morning in order to be the first seated in the train. However, since you got the tickets, you also have his sit number. So Emil chose to sit wherever he liked in the train. Then, the one after the other, each passenger entered the train, and if someone already was seated at their place, they strongly grumbled before picking a random place among the available ones.
Finally, you arrived. What is the probability that the only sit available is exactly yours ?
