Hey Joseph, not all the companies are the same. I know many package forwarding companies like DHL, Global shopaholics, and PlanetExpress that repack items in smaller boxes to save money on shipping. One of the best company is Global shopaholics that repack items in the smallest possible box without compromising your shipment's safety, and I have tried them.
15 pencils, but if specified otherwise then its 29 x 15.
I believe the relative sizes of HD boxes or regular cable boxes may depend on the provider through which you choose to get HD or regular cable. You should check with the provider you are considering to determine if their HD boxes are bigger or smaller than their regular cable boxes.
the puzzle box
there are 33 boxes because if you count 3 that's 3. then the 2 boxes inside each big box that's 6 small boxes. and that makes 9 boxes. then you have 4 even smaller boxes. 4 multiplied by six makes 24. then you add 9 plus 24 and get 33.
The answer is 20832
The USPS has flate rate boxes that as long as the item fits inside the box it ships for a flate rate. As long as you are shipping within the US, the price of the smaller boxes are $5.20 and if you use their online services you'll save even more and only pay $5.00. The large flat rate boxes are $14.95 and with the online services you pay only $14.20. So, you can save by ordering smaller boxes for your smaller orders and save even more when you use their online services.
One of the best ways to get boxes are the pre-paid priority shipping boxes from the USPS. It's easier to do pre-paid boxes for smaller businesses and you can order them in bulk.