That's a nice one question, thanks for posting it.

1)
We are ok it is useless by itself.

2) Car Y arrives in Town A at the same time Car X arrived in Town B
We have two cars. We have two different speeds. We know X starts 15' before Y, and they arrive at their destination at the same time and drove the same number of kilometers; we can infer that the speed of X is lower than the speed of Y.

You have the city A, the city B and the middle of the distance is M.
A-------------M----------------B

Imagine X see Y between A and M, there is a big problem because X is slower than Y and X has to drive more kilometers than Y ! X will never arrive at B at the same time Y does at A.
That is the same if they see each other at M, it's over for X, it is slower than Y.
So, X will see Y between M and B, closer to B than to A.

So your answer is B

thanks!