There is no set length for the number of pages for a first-class letter. This designation simply guarantees it will be delivered quickly and securely.
A standard first-class letter typically consists of one to two pages. If the content exceeds this, it may require additional postage or be classified as a package.
It's not the number of pages that count, because there are diffeent weights of paper available. A first class stamp pays for the first Ounce of a Letter's weight.
Eastern Standard Tribe has 224 pages.
A standard U.S Passport has 12 pages
The Letter of Marque has 284 pages.
Letter from Peking has 252 pages.
The Crooked Letter has 640 pages.
5 pages-102 pages
the book dead letter has 147 pages
The Vivero Letter - novel - has 290 pages.
The Last Letter Home has 311 pages.
Letter to a Christian Nation has 96 pages.
So Long a Letter has 90 pages.
European standard is 32 pages I think, and US is 24 pages but you can add pages to a US passport.