How long mail takes is going to depend on many factors along the way. Many factors, indeed, though with regard to how long does priority mail take, the answer is, not long. In fact, the United States Postal Service says your package or envelope will arrive within two days.
Both the 2009 IRC and the DCA6-09 allow #2 southern pine 2x10s to span 13 feet 1 inch at 24 inches on-center at a design load of 50 psf. That means these joists can span the 12-foot depth of the deck, and the beam can be located at the perimeter. Nine joists will be needed for the 16-foot width.
In general, double wide homes come in these dimensions: 8, 10, 12, 14, and 16 feet wide. 42, 48, 50, 56, and 60 feet long. This does not include any porches, awnings, covered parking, sheds, additions, etc. So, a double wide can be from 672 sqft to 1920 sqft. Of course these are general numbers and actually many manufactured homes can be ordered from the factories with adjustments made to the size over all. Now, a doublewide is always two sections.