Question

a news paper has 4 pages missing i can tell you that pages 6 and 19 are missing.
how many pages were in the original news paper?

Answer 1

A newspaper has 4 pages missing i can tell you that pages 6 and 19 are missing. How many pages were in the original newspaper?

In newspaper pages 1,2,n-1,n are in one list of paper (n - number of last page)

pages

3,4,n-3,n-2 in another list,

therefore in one list we have pages with numbers:

$2k + 1,2k + 2,n - 2k - 1,n - 2k$ ，k- some integer number (0,1,2...)

Therefore:

$6 = 2k + 2 \Rightarrow k = 2$

$19 = n - 2k - 1 \Rightarrow n = 19 + 2 * 2 + 1 = 24$

Answer: in the original newspaper were 24 pages