This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
[{'content': 'Study the following table of population in a district and the average population served per doctor. Calculate the harmonic mean:\\r\\n \\r\\n\\r\\n\\r\\n\\r\\nAREA\\r\\n\\r\\n\\r\\nPOPULATION SERVED PER DOCTOR\\r\\n\\r\\n\\r\\nPOPULATION\\r\\n\\r\\n\\r\\nNUMBER OF DOCTORS\\r\\n\\r\\n\\r\\n\\r\\n\\r\\nRURAL\\r\\n\\r\\n\\r\\n1000\\r\\n\\r\\n\\r\\n50000\\r\\n\\r\\n\\r\\n50\\r\\n\\r\\n\\r\\n\\r\\n\\r\\nURBAN\\r\\n\\r\\n\\r\\n500\\r\\n\\r\\n\\r\\n50000\\r\\n\\r\\n\\r\\n100\\r\\n\\r\\n\\r\\n\\r\\n\\r\\nTOTAL\\r\\n\\r\\n \\r\\n\\r\\n100000\\r\\n\\r\\n\\r\\n150\\r\\n\\r\\n\\r\\n\\r\\n \nSelect and explain. \nA. 500, B. 567, C. 667, D. 750', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Calculation of harmonic mean is as follows: (50000+50000)/(50000/100+50000/50)=667 Ref : Medical biostatistics, 1st edition pg: 118', 'role': 'assistant'}]