History sources include diaries, letters, interviews, oral histories, photographs, newspaper articles, government documents, poems, novels, plays, and music. The collection and analysis of primary sources is central to historical research.
If you divide 105 days by 7 that's 15 weeks then you multiply 47 by 15 which is 705 then you multiply 65 by 15 which is 975 then you add 975 to 500 and subtract 705 which will give you 770
