Translation:Definition, description or identification of a problem.
I doubt many people noticed (or care), but the lack of an Oxford comma in this sentence is apparently correct in Spanish grammar.
"Problema" is masculine. In fact, several words ending that way are, since they come from Greek.
No, it's not a complete sentence, but adding articles to it wouldn't make it a complete sentence. It's missing a verb (a predicate) and possibly an object, if the added verb is transitive.
But it's still a legitimate sentence fragment. Duolingo presents us with many sentence fragments that are still useful to translate and learn from and which might be found in ordinary use of the language.
Nope, in this case there is no collision since "o" and "identificación" do not start with the same sound. Essentially:
- and = y (e if the next word begins with an "i" sound)
- or = o (u if the next word begins with an "o" sound)
Check out this page: http://spanish.about.com/cs/grammar/qt/y_o.htm