Breakdown of Этот вариант стоит тридцать баллов.
этот
this [f: эта, n: это]
стоить
to cost
тридцать
thirty
вариант
option
Questions & Answers about Этот вариант стоит тридцать баллов.
Why do we use the form баллов instead of just баллы?
This is because of the number тридцать (thirty). In Russian, numbers ending in zero (like 10, 20, 30) or 5 through 9 require the following noun to be in the genitive plural case. The base word is балл (point), and its genitive plural is баллов.
Does the number тридцать change its form here since it comes after a verb?
It is technically in the accusative case here because it tells us the specific amount that the option costs. However, for numbers like тридцать, the accusative form looks exactly the same as the dictionary (nominative) form.
Doesn't the verb стоит mean "stands"?
It depends on the stress! There are two verbs spelled exactly the same way. СтОит (stress on the first syllable) means "costs". СтоИт (stress on the second syllable, from the verb стоять) means "stands". The context of "thirty points" makes it clear that it means "costs" here.
Why is the word for "this" spelled as Этот?
The word for "this" has to match the gender of the noun it describes. Вариант (option) is a masculine noun because it ends in a consonant, so we use the masculine form Этот.