Currently in the US a Forever stamp costs 44 cents and I will assume that this the type you are referring to, so a book of twenty stamps would cost you $8.80.
42
20 in a book, 100 in a roll (assuming you are not talking about a collectors book of stamps).
18.5
The average cost of a plain book of stamps is usually around 14-15 dollars. For a half book of stamps the cost normally ranges from 5-8 dollars.
One book of stamps can cost approximately $10 at the post office. This will include 20 stamps that are personalized. You can buy larger amounts at $.48 per stamp.
20.25/9 = $2.25
Four books would cost twenty rupees.
One stamp will cost 46 cents. A book of 20 stamps will cost $9.20. There was not information about a "pele stamp."
In the US you can buy two 10- cent stamps, four 5-cent stamps. five 4-cent stamps, ten 2-cent stamps or twenty 1-cent stamps for 20 cents at most post office windows.
we don't know how much it cost so check back another day or look it up in a book or the Internet
20 stamps
Back of the Book stamps are those that are used for special purposes. These include Air Mail stamps, Special Delivery stamps, tax, official, and postage due stamps. In stamp albums and catalogs they are found at the 'back of the book.'