Combination
Purpose 
Returns the number of ways to uniquely choose numberOfChoices items from a set of size setSize.
Format 
Combination(setSize;numberOfChoices)
Parameters 
setSize - any numeric expression or field containing a non-negative numeric expression
numberOfChoices - any numeric expression or field containing a non-negative numeric expression
Data type returned 
number
Originated in 
FileMaker Pro 7.0
Description 
This function is useful in statistics, combinatorics, and polynomial expansions. The values returned by this function are referred to as combination coefficients. They form Pascal’s triangle.
Equation
Examples 
Combination(5;2) returns 10 for a set consisting of {a, b, c, d, e} because the unique choices when choosing two at a time are {ab, ac, ad, ae, bc, bd, be, cd, ce, de}.
(13 * 12 * Combination(4;2) * Combination(4;3)) / Combination(52;5) returns 0.00144057..., which is the probability of being dealt a full-house in 5-card poker (less than a 1% chance).
Related topics 
Functions reference (category list)
Functions reference (alphabetical list)
About formulas
About functions
Defining calculation fields
Using operators in formulas