A chunk of pages is missing from a book. The sum of the missing page numbers is 9808. What are those page numbers?
a1 ==> first page - odd number
ak ==> last page even
av=average= 1/2* (a1+ak )= odd number of halves
9808=16*613=32*306.5
There are 32 page numbers missing (16 sheets),:
a1=306-15=291
ak=307+15=322