His answer was "Neither win" and it took him 1 minute and 24 sec using no pre-defined algorithm or heuristic.
He said his process of thoughts was:
"I figured it would take 10 hours for car A to finish 100 miles and it would take twice that long for car B. Since Car B is already halfway there when car A starts, then they would arrive together"
I as 40 year old man, approached it intentionally naively (eg. I did not go looking for an optimal solver first) by making a drawing and attempting to derive the algorithm. It took me ~3 minutes to come to the same conclusion but at the end I had a series of equations, but no algebraic proofs.[1]
So now you have a human child reference metric if you want it.
[1]https://twitter.com/AndrewKemendo/status/1766872572300235022