Winnie flipped her book to the middle. The sum of the two facing page numbers is 161.
- What are the two page numbers? Give your answer in this format. (Eg 1, 2)
- How many pages are there in the book?
(a)
Smaller page number = 1 u
Bigger page number = 1 u + 1
Sum of the two facing page numbers
= 1 u + 1 u + 1
= 2 u + 1
2 u + 1 = 161
2 u = 161 - 1
2 u = 160
1 u = 160 ÷ 2 = 80
Smaller page number
= 1 u
= 80
Bigger page number
= 1 u + 1
= 80 + 1
= 81
The two page numbers are 80 and 81.
(b)
Since Winnie flipped her book to the middle, the number of pages on the left side and the right side of the book is the same.
Total number of pages in the book
= 80 + 80
= 160
Answer(s): (a) 80, 81; (b) 160