This question is a bit lengthy. However, any answers would be appreciated. Thanks.?

In an undisclosed Mediterranean country trains run in a frequency of 2 per hour. In a customer survey, the passengers complained that average waiting time to a train is too long for a randomly arriving passenger. The management added a third train.


In view of the above arguments, related to self-weighted averages, can you describe circumstances under which an addition of a third train will INCREASE the average waiting time of a passenger that arrives randomly at the train station.

This question is a bit lengthy. However, any answers would be appreciated. Thanks.?
If you mean that the frequency is now 3 trains per hour, then NO the average waiting time will decrease. Before it was 30 mins, now it's 20 mins.





If however the trains are scheduled to arrive within 1 minute of each other, then if you miss them, you have to wait nearly an hour.
Reply:If adding a 3rd train to the same route means that three trains will now arrive per hour at the station, then NO, I can not see how this would increase waiting time for a randomly arriving passenger.
Reply:Not if you leave the times of the first two trains the same. If you add a third train and change the times of the first two trains it is possible.





If the two trains arrived on the hour and the half hour you would wait 15 minutes on averate. If you have three trains that arrive on the hour, one minute after the hour and two minutes after the hour the averate waiting time would be greater.

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