Linq to Lambda Expression c#

Question

var ListInOrder = (from f in finaldatelist
               group f by new { f.RoomID, f.RateGroupID } into g
               select g);

What are the lambda expression for the into g and select g part?

This is what I got now:

 var ListInOrder = finaldatelist.GroupBy(x => x.RoomID, x => x.RateGroupID).Select();

Answer 1

finaldatelist.GroupBy(x => new { x.RoomID, x.RateGroupID });

Answer 2

It should be something like,

var ListInOrder  = finaldatelist.GroupBy(cm => new { cm.RoomID, cm.RateGroupID}, 
             (key, group) => new { RoomID= key.RoomID, RateGroupID = 
              key.RateGroupID});