How would you say in Greek: how much time does it take to go from Athens to kalamata?

Is there a difference in meaning between "προτου" and "πριν" or can we use them interchangeably?

Why would you use περισσότερο in this sentence? I am not clear why you use περισσοτερο ( in neuter, singular here ), rather then using περισσότερες in the below question? Ποίες καραμέλες σου αρεσουν περισσότερο;