Question: how many seats in the las vegas arena
[{'answer': '20,000', 'provenance': [{'wikipedia_id': '39717296', 'title': 'T-Mobile Arena', 'start_paragraph_id': 5, 'start_character': 182, 'end_paragraph_id': 5, 'end_character': 188, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}]