diff --git a/app/models/group.rb b/app/models/group.rb
new file mode 100644
--- /dev/null
+++ b/app/models/group.rb
@@ -0,0 +1,13 @@
+class Group < ActiveRecord::Base
+  has_many :groups_problems, class_name: GroupProblem
+  has_many :problems, :through => :groups_problems
+
+  has_many :groups_users, class_name: GroupUser
+  has_many :users, :through => :groups_users
+
+  #has_and_belongs_to_many :problems
+  #has_and_belongs_to_many :users
+
+
+end
+