Question 2
The diagram shows the roads between cities A and B. An starts at A and can only travel upward or rightward. Bình starts at B and can only travel downward or leftward. They start together at the same speed. How many different ways can they meet?
Clarification: the small grid segments have equal length; count pairs of routes up to their meeting, not just meeting locations.
Clarification: the small grid segments have equal length; count pairs of routes up to their meeting, not just meeting locations.