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By the 20th century, the saloon, or lounge bar, had become a middle-class room[citation needed]—carpets on the floor, cushions on the seats, and a penny or two on the prices,[citation needed] while the public bar, or tap room, remained working class with bare boards, sometimes with sawdust to absorb the spitting and spillages (known as "spit and sawdust"), hard bench seats, and cheap beer[citation needed]. This bar was known as the four-ale bar from the days when the cheapest beer served there cost 4 pence (4d) a quart.[citation needed]

In pence, what did the cheapest beer cost in the four-ale bar?
4