O S. The series contains the first letter of each month in alphabetical order (April, August, December, February, January, July, June, March, May, November). O and S represent the remaining 2 months, October and September.
I appear in the morning but am always there. You can never see me though I am everywhere. By night I am gone, though I sometimes never was. Nothing can defeat me but I am easily gone.
A bookworm eats from the first page of an encyclopedia to the last page in a straight line. The encyclopedia consists of ten 1000-page volumes and is sitting on a bookshelf in the usual order. Not counting covers, title pages, etc., how many pages does the bookworm eat through?
On a book shelf the first page of the first volume is on the “inside”, so the bookworm eats only through the cover of the first volume, then 8 times 1000 pages of Volumes 2 – 9, then through the cover to the 1st page of Vol 10 for a total of 8,000 pages.
Note: The question asks how many pages, not how many sheets of paper.