Help on The Meeting Place Cannot Be Changed (CodeForce)

Problems and Contests
#1

Hey guys, this is my first time here so I might make some mistakes writing this, but here the problem is called The Meeting Place Cannot Be Changed, link: https://codeforces.com/contest/782/problem/B
I have been working on it for a while, but I can’t find a good way to determine where they meet at a non-integer point, any hints or tips? Thank you!

#2

You…don’t?
IIRC this was in the Binary Search module, so try to think about this from the perspective of binary search.

#3

Try to find whether the friends can meet together in a particular amount of time. Don’t try to binary search on the coordinate point where they meet.