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?
Quick Answer. The maximum weight for a First-Class letter envelope, which is 3.5 ounces, according to the United States Post Office. There are also size and proportion requirements to consider when sending mail First-Class. Letter envelopes must be rectangular, and they must not exceed 11.5 inches in length or 6.125 inches in height.