A guy has two girlfriends: en the East and the West. He works near 5 Points Mart
ID: 3799110 • Letter: A
Question
A guy has two girlfriends: en the East and the West. He works near 5 Points Marta
station and finishes his job at a random time of the day. Rather than deciding to
which of two girls take the train - he leaves the choice to a chance: he takes the
train (East or West) whichever comes first. The west train comes every 10 min
and the East train comes every 10 min throughout the day. Nevertheless, after
half a year he finds out that he is coming to east girl several time more frequently
than to the West girl. Why???
Explanation / Answer
Assume the East train arrives at 09:00, 09:10, 09:20, etc. and the West train comes after three minute at 09:03, 09:13, 09:23, etc.
As given the ten minute interval,
considering it from 09:00 to 09:10. If the man arrives between 09:00 and 09:03, the 09:03 West train will be the first to arrive
(assuming that he doesn't arrive at exactly 09:00). If the man arrives between 09:03 and 09:10, the 09:10 East train will be the
first to arrive. In any ten minute period, the East train will be the first.
Hence it is possible to reach to East girl mostly.