Breakdown of Кто-нибудь может решить задачу номер тринадцать или четырнадцать?
мочь
to be able to
решить
to solve
задача
task
или
or
Questions & Answers about Кто-нибудь может решить задачу номер тринадцать или четырнадцать?
Why are тринадцать and четырнадцать in their basic dictionary forms here?
When numbers are used as labels or IDs, like "problem number thirteen", they don't change their endings. They stay in their basic (nominative) form. You only change a number's case or worry about complex noun rules when you are actively counting a quantity of things (like "thirteen problems").
Why use кто-нибудь instead of кто-то for "anyone"?
Both words mean "someone" or "anyone", but the -нибудь ending is used when the person is completely unknown or hypothetical, which is very common in questions. If you used кто-то, it would imply you think a specific person can solve it, but you just don't know who.
Why is the verb может (can) in the singular form if the speaker might be addressing a group?
The pronoun кто-нибудь (just like кто) always requires a singular verb in the third person (the "he/she/it" form). Even if you are asking a whole classroom "can anyone...", grammatical rules treat кто-нибудь as a singular entity.
Why is the word for "problem" written as задачу?
Задачу is the accusative case form of the feminine noun задача (task/problem). It takes the -у ending because it is the direct object of the verb решить — it is the thing that is being solved.