How to get the number of rows per room

[Miro]

Hi Community,
I have a room list
room name last name   class age id student
106    Andre
106    null
107    null
108   Timo
I need to indicate whether the room is single or double. I was able to duplicate the table and group by in power query
106 -2
107 -1
108-1
but then i am merging back to the initial table, is there any other way jut to keep all the steps in one table?? without having to duplicate and merge?
Thanks

[Miro]

Oh, thats a nice trick, thank you!

[olgad · Accepted solution]

Hi there,
there is an option to pick all when you group by and count rows

then tick your columns except for the ones your were grouping by and expand

and there you have your table back as it was plus the count of rows.

Please kudo and accept the solution if it works for you.