"Has everyone got their floors?" I asked. 

After a moment's silence, a young female voice from the rear said, "His or her."

"I beg your pardon?" I said.

"His or her.  It's 'Has everyone got his or her floors?'  Your pronouns don't agree."

"And shouldn't it be 'his or her floor', not 'floors'?" a young man piped up. 
"Each of us gets off at only one floor."

"And wouldn't it be better to say 'Does everybody have?' rather than 'Has everybody got?'" a third voice chimed in.

I stood corrected - and red faced.  But I was glad to know that good grammar is alive and well.