Does deleting the login retain the permissions given via group membership?

Question

I have a windows group account added as login in sql server. The group contains around 100 members.

The above windows group login is given specific database level permissions like db_datareader, db_ddladmin, etc.

Recently I have manually added one of the users from the above group into the SQL security as login and given him sysadmin role. Subsequently this user has created couple of SQL jobs.

I have been asked to remove sysadmin permissions from this user.

Question 1: Suppose I untick the sysadmin role from this user, and keep only public ticked, then will he inherit permissions originally given via the windows group or not? Will he get the most restrictive privilege, that is - public - and thus loose the permissions given via the group?

Question 2: Suppose I delete the jobs and then delete this user from the login, then will his permission revert to permissions originally given via the windows group or not?

Answer 1

Permissions are cumulative; i.e. the permissions granted through membership in the Windows Group would be added to whatever permissions were granted via the individual login.

If you simply drop the individual login, the user will revert back to the permissions granted via the Windows Group login.