Answer:
[tex]\boxed{13}[/tex] pages
Step-by-step explanation:
Divide the total number of pages by 5 to get how many sets of every 5 pages will contain 2/3 of a page of advertisements.
[tex]\frac{98}{5} = 19.6[/tex]
Multiply this value by [tex]\frac{2}{3}[/tex] to get the total number of pages.
[tex]19.6 * \frac{2}{3} \approxeq 13[/tex] pages