11. In 2011, a total of 171.1 billion items were sent through the U.S. mail. Of these, 78.8 billion items were first class mail. What percent of the items, to the nearest tenth, were pieces of first class mail? Solution total of 171.1 billion items Of these, 78.8 billion items were first class mail Percent of first class mail = (78.8/171.1)*100 =0.4605*100 = 46.05% = 46.1% (nearest tenth).