I do agree some questions are not straight forward and it comes to how we understand the question. I had the same doubt but whichever i choose as the corner, the answer to the puzzle was still 15...you either start at 2 or at 3 based on what you consider as the corner.
I understood the running race puzzle in a different way and assumed that my solution was correct. But @ksolymosi said that the clues were to be understood differently.
End of the day, these daily brain games give a good workout to my brain and any rewards I get along is an added bonus. So, lets enjoy and solve more puzzles. :-)
Actually, for the 'corner' puzzle, you can obtain an answer of 14, if you start at the corner 2 (see image below).
Ultimately, @ksolymosi said to me regarding her wording for that DBG: "probably it was misleading".
Which is fine. Like you said, this is fun, still :)
Wow, nice! I like your answer better than mine. I assumed no repeat junctions, so hadn't thought about this solution. My answer was actually: "15. "Corner" is a bit confusing, but here it doesn't matter. Either go from the top right 3 (edge of diagram) to 5, 2, 4, 1 or 5, 1, 4, 2. Or go from top left 2 (place at which two converging lines or surfaces meet) to 5, 1, 4, 3." This was because I too was unsure about what ksolymosi meant with "corner". Luckily, it was accepted.
Thanks for the kudos :D
At least you got your answer accepted - that seems to be the hardest part of the DBG series lol