A young man lives in the town of Bee near a railway station. He has two friends, one staying at Cee and the other at Dee. To visit the friend in Cee he takes a train on the downtown side of the platform; to visit the friend living in Dee he takes a train on the uptown side of the same platform. Since both friends are equally dear to him, he lets chance determine which friend he'll visit. He reaches the station at a random moment each Sunday afternoon and takes the first train that comes along.
Curiously, though both the trains arrive at the station equally often — every 10 minutes, he finds himself spending more time with the friend in Cee. In fact, on an average he goes there 9 times out of 10.
Can you think of a reason why this should be so?