Your question is Probability with Triangle Ants. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
3 ants moving along the sides of a triangle. Probability of collision?
Asked in the Interview stage. Assume one ant starts at each vertex of an equilateral triangle. At the start, each ant independently chooses clockwise or counterclockwise movement with probability 1/2 and maintains that direction at the same speed. A collision occurs if any two ants meet on a side.