A nerdy guy, eats dinners during week days either with his mom or with his girlfriend. The girlfriend complains that he is spending on average four dinners with his mom and only one with her. The guy defends himself as $$My girlfriend and mom live in the opposite directions of the metro line that I take after work. Both trains come at every $10-$minute intervals $($no uncertainty here$).$ When I go to the station at a random time; whichever train comes first, I take that one. So$,$ my choices are random, what I can I do$?$ What can you say about reasoning? Could he be right? $($Sorry about this old$-$style question, there are actually business problems like this but takes too long and they are not as interesting$).$