".... for permanent cookhouse duties, I've decided that Private Quelch is just the man for the job."

“… for permanent cookhouse duties, I’ve decided that Private Quelch is just the man for the job.” Of course, it was a joke for days afterwards; a joke and a joy to all of us.
(a) Which word in the extract is opposite to ‘temporary’?
(b) Why was Private Quelch given cookhouse duties?
© What was the joke for days afterwards?

(a) The word is ‘permanent’.
(b) Private Quelch had disturbed the Corporal’s lecture by showing off his knowledge of grenades and was thus given this duty as punishment.
© Quelch being assigned cook house duties was the joke for days afterwards.