The Bornean orangutan is listed as Endangered and numbers approximately 41,000, while the Sumatran orangutan is considered Critically Endangered with an estimated population of 7,500. A century ago, more than 230,000 orangutans likely roamed in the wild.
Making the world better, one answer at a time. If you go to the United States Postal Service web-stie, you will find that one US First class stamp ($0.42) will cover the cost to mail a letter that weighs up to 1 ounce, about 28.35 grams. Thus, the average weight of a letter is one ounce or less. If you go to the United States Postal Service web-stie, you will find that one US First class stamp ($0.42) will cover the cost to mail a letter that weighs up to 1 ounce, about 28.35 grams.  Minor edit?
Basis Weight Standards. When you're sending letter mail via USPS you must use an envelope with a minimum basis weight of 20 pounds. Mailed booklets must also be made from paper with a minimum basis weight of 20 pounds. Folded self-mailers made from a single sheet of paper must have a minimum basis weight of 28 pounds. If it's made from multiple sheets of paper then the minimum basis weight is reduced to 24 pounds.