There will be 15 unused slots in the schedule, since there are 60 available but only 45 games in the round-robin. If a team has only one game at a venue, then there must also be another team with only one game, and in such cases there are only 4 games to be played, meaning that one of the time slots is not required. In all other cases there will be 5 games at a venue as this gives each of the 5 teams scheduled to travel there exactly 2 games each. I hope the solution below is useful to you (also attached in Excel format) - you need to be logged in to see the image and attachment.