"The trip is long."
Translation:Die Reise ist lang.
"Die Fahrt ist lang" is not permitted for this question.
That's right. It's not on the list of accepted answers that the Pearson editors added to this sentence.
You can report it if you want but I don't think anything will happen.
(background info: https://forum.duolingo.com/comment/24066422/Interference-from-the-Pearson-course )
Why can't Farien be used
There's no such word in German as Farien.
Farien refers to a vacation in time?
A vacation is Ferien (with e not with a).
It refers to time off from school.
It does not refer to a trip.
You can spend you Ferien at home and they're still Ferien.
You can go on a school trip and it's a strip but not Ferien.