Translation:They put at most two chairs in each room.
There is no "seat" in that sentence, however, the last time I came across this question the word "cadeira" was there. I think it's just omitted from some variations of this question. That was the first time I saw "cadeira" in these variations, and the ones without it don't usually mark you wrong if you omit "chair/cadiera". Usually, because sometimes Duo thinks you're a mind reader