Planning multiple trips with people and rooms

I am trying to plan various combinations of trips, people, and room assignments.

For the sake of simplicity, let’s say there are:
25 trips this year
10 two-person rooms available for each trip.
300 people who may go on these trips. Many will go on more than one trip.

I have tables for people, for trips, and for rooms.

How/where do I combine these so that I can plan who goes into what room on each trip?