May read the same number of pages of a book each day. After 8 days, 5/6 of the book remained to be read. After another 20 days, there were still 45 pages left to be read. How many pages had this book?
Let P = number of pages in the book and p = number of pages per day.
P/6 = 8p She read 1/6 of the book in 8 days So p = P/48
P - 45 = 28p 45 pages to go after 28 days. So P-45 = 28*P/48
P(1-28/48) = 45
P*20/48 = 45
P = 45*48/20 = 108
There are 108 pages in the book.
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