Mary flipped her book to the middle. The sum of the two facing page numbers is 209.
- 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 = 209
2 u = 209 - 1
2 u = 208
1 u = 208 ÷ 2 = 104
Smaller page number
= 1 u
= 104
Bigger page number
= 1 u + 1
= 104 + 1
= 105
The two page numbers are 104 and 105.
(b)
Since Mary 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
= 104 + 104
= 208
Answer(s): (a) 104, 105; (b) 208
