Unfortunately, when Billy came home from school, he had five friends with him. Not to be stumped, Mom asked Billy and another boy to share a seat for a while. Then she put the second guest into the second seat, the third into the third seat, the fourth into the fourth seat. Then looking at the remaining empty (fifth) seat, she said to the boy sharing Billy's chair:
"You can now go sit this this last seat. Since you are Billy's fifth guest, everyone should now be seated."
Did Billy's mom really manage to put six people into five seats?