Final answer:
The sum of the page numbers of an open book, which includes two consecutive integers, is always an odd number. The left page is even and the right page is the next consecutive odd integer.
Step-by-step explanation:
The student is asking a mathematical question about the sum of two consecutive integers, which are the page numbers of an open book. When a book is open, the left page is always an even number, and the right page is the consecutive odd number. Since the sum of any even and odd number that are consecutive is an odd number, the sum of the left and right page numbers is an odd integer. Let's consider the left page number as ‘n’, which is an even number; therefore, the right page would be ‘n+1’. Summing the two gives us ‘n+(n+1)’, which simplifies to ‘2n+1’—an odd number.