Can I change devices permissions with chmod?

If you change a files permissions to chmod 755 in Linux what kind of permissions are assigned to the group that owns the file?

• Answer:

  The group has read and execute permissions. The number is octal; the digits pertain to owner, group and all users respectively. The binary representation in three bits of each digit gives read, write and execute permissions respectively. Thus the middle digit, for group permissions, a 5, is binary 101, indicating read and execute but no write permission.