Translation:Outside, there are chairs like inside.
Awkward sounding I am finding the translations in this lesson in English. Getting them right I rarely do.
I don't think you can avoid the phrase "There are..." in a good English translation of this sentence. The Hungarian sentence is about existence.
It is not a general statement comparing two kinds of chairs (which is how I read your sentence.)
I don't know exactly what the sentence to be translated means. "Kint olyan székek vannak, amilyenek bent." ??? I can think of two situations: a) Kint (is) vannak olyan székek, mint bent. (=there are SOME chairs outside that are like the ones inside). b) Kint (is) olyanok a székek, mint bent. (=ALL the chairs outside are like the ones inside). The accepted translation has the meaning of a), but I would say Mitja Šterman's translation could be pretty good with the articles added. (The chairs outside are like the ones inside.) This was my sentence which failed :))
You probably know it by now: the Hungarian sentence means that all the chairs outside are like the ones inside, so your b) is correct. The English sentence should be like 'Outside, the chairs are like the ones inside.'
"Outside, there are chairs like inside." - means (or may mean) that there are chairs outside like there are chairs inside - i.e. the fact that there are chairs is the similarity, rather than the chairs being similar.
"There are chairs outside like the ones inside" is a better translation.