Answer: ¿Cuántos estudiantes hay en el aula?
Translation: How many students are there in the classroom?
Step-by-step explanation:
In Spanish, interrogative adjectives are used before countable and uncountable nouns and must always match in gender and number with the noun about which they interrogate. Since "estudiantes" is a masculine and plural noun, its adjective must also be masculine and plural: ¿Cuántos". This word has a written accent, because in Spanish all the interrogative words have a written accent.
Spymore