Durations and Slots for Discussions

I have a discussion that 2 people have signed up for.

The first signed up for 15 min (based off of the pink 15 min slot). When the second person signed up, the 30 min slot turned pink. The conversation sign up emails for discussions do not mention the duration. Does this mean the 2nd person signed up for a 30 min discussion?

This seems obvious to me, but I want to be sure.

In a group discussion the duration is determined by the number of participants. If there is only one participant it is 15 minutes long, if there are 2 it is 30 minutes long. Obviously, you speak to them both for 30 minutes. It is a group discussion.

And you can set the maximum duration for a conversation, and hence the maximum number of participants. I find that a one-hour, five-way conversation fries my brain (though in practice I have only had one that was fully booked) so I now make most of mine half-hour, 2 student conversations. If only one person signs up, it automatically becomes a 15-minute one-on-one. Incidentally, most people seem to prefer these. I seem to attract shy students!