In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.
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Question: When did star spangled banner became the national anthem?

Answer: March 3, 1931


Question: Who's the best selling artist of all time?

Answer: The Beatles


Question: How many rooms does the luxury crown metropol perth have?

Answer:
405