Answer: Loki will win the race.
Explanation:
Rje following took place based on the question:
Doug gets a 20 meter head start, but then he sits down and refuses to walk. It didn't finish the race.
Pogo gets a 10 meter head start and walks 1 meter every second. Since he has 20m head start, he will have 20 meters left to walk which will be take 20 seconds.
Loki gets no head start and walks 3 meters every second. To walk 30meter will be: (30/3) = 10 seconds.