The English is wrong here. Not only is an article not required, it's actually wrong. Just as you wouldn't say "I live in THE flat 36", you wouldn't say "where is THE carriage number 9" (and, incidentally, "carriage" is a more natural translation of "вагон" - but I've reported that so many times I've given up on it being allowed
I reported about the audio - but I only get the options to report the audio if it doesn't sound right. There's also this option: it's not taking my recording on the last word.
This exercise is not picking up my word дев'ять - but picks up all the other words. I've done this dozens of times already and say it exactly mimicking the speaker, repeating, saying it louder - it doesn't matter what I do, it's not picking it up.
Numbers have issues for some reason. Even if you literally play the Duolingo's original audio back to it during the speaking exercise, it will not register it. It's something on the deeper level of Duolingo that volunteering contributors/moderators have no influence on; I've notified the Duolingo staff already. It's not only for this exercise, it's a general thing. One person from the Norwegian course commented that they have similar issues.