Hello, 200001!

I don't understand the question . . .

As written, the problem is quite silly.

If a room had to seat 20 adults andtheir position didn't matter,

is it simply 20! to work out the number of combinations?

I must assume quite a bit that wasn't explained.

I assume: "number of combinations" means number of seating arrangements.

I assume: there are20 chairs in the room.exactly

I assume: there will beperson seated in any one chair.one

Sincetheir position doesn't matter, any person can sit in any chair.

Therefore, there isoneseating arrangement.