The value of the book sold in the first week = 285121
The value of the book sold in the second week = 400768
Total number of books sold in the first and second week = 285121 + 400768 = 685889
Total sale of the two weeks = 685889
Sale of the second week is greater than that of the first week
More book sold in the second week = 400768 – 285121 = 115647
Therefore the amount of 115647 more books were sold in the second week.