The phenomenon that large packages are cheaper than small packages can be considered based on the following assumptions:
1) The cost of packaging a commodity is the fixed cost plus the packaging cost of the surface area of the commodity outer box, the former is constant, and the latter is proportional to the packaging surface area.
2) Suppose that the commodity we consider is a cube. Its weight is proportional to its volume.
Then, based on the above assumptions, we assume that the side length of the small package is a and the side length of the large package is 2a, and the weight ratio of the two is 1: 8. In terms of package cost, in the case of M, small package = m+6a 2 * k, and large package = M+2A4A2 * K.
For other shapes of packaging, a similar method can be used to calculate. M can be understood as fixed cost, such as depreciation cost of packaging machine. K stands for the unit cost of increasing the packaging area, such as the cost of paper and ink.