Wolfram Computation Meets Knowledge

Birthday Problem Approximation

The birthday problem, or birthday paradox, concerns the probability that, in a set of n randomly chosen people, some pair of them will have the same birthday.

The probability that m people will have the same birthday depends nonlinearly on k, the total number of people and the number of possible birthdays.

Formula

QuantityVariable["n", "Person"]/E^(QuantityVariable["n", "Person"]/(QuantityVariable["d", "Unitless"]*QuantityVariable["k", "Person"])) == (QuantityVariable["k", "Person"]!*Log[(1 - QuantityVariable["p", "Unitless"])^(-1)]*QuantityVariable["d", "Unitless"]^(-1 + QuantityVariable["k", "Person"])*(1 - QuantityVariable["n", "Person"]/(QuantityVariable["d", "Unitless"]*(1 + QuantityVariable["k", "Person"]))))^QuantityVariable["k", "Person"]^(-1)

Forms

Examples

Get the resource:

In[1]:=
ResourceObject["Birthday Problem Approximation"]
Out[1]=

Get the formula:

In[2]:=
FormulaData[ResourceObject["Birthday Problem Approximation"]]
Out[2]=

Use some values:

In[3]:=
FormulaData[
 ResourceObject[
  "Birthday Problem Approximation"], {QuantityVariable[
   "n","Person"] -> 23}]
Out[3]=

Source Metadata

Publisher Information