If the sentence in the singular is:

> The butcher's and the hairdresser's are closed on Sunday.

What happens to the genitive if I want to make it plural?

1. >Butchers and hairdressers are closed on Sunday.
2. >Butchers' and hairdressers' are closed on Sunday.
3. >Butcher's shops and hairdresser's salons are closed on Sunday.

In British English they call it the butcher's, because "shop" can stay implicit. My question is: if I want to say all the butcher's shops are closed, can I still leave the word "shop" implicit and therefore say: Butchers' are closed on Sunday? Why would I loose the genitive in the plural if I had it in the singular? If I drop the apostrophe and I say the butchers (plural) it would mean the butchers = the people who work in those shops.