The COMBINA function returns the number of ways to choose some number of objects from a pool of a given size of objects, including ways to choose the same object multiple times (also known as choosing with replacement).
Parts of a COMBINA function
COMBINA(n, k)
Part | Description | Notes |
---|---|---|
n | The size pool of objects to choose from. | * Given n values should be greater than or equal to 0. |
k | The number of objects to choose. | * Given k values should be greater than or equal to 0. |
Sample formulas
COMBINA(5, 3)
COMBINA(A1, B1)
Notes
- The order of the chosen objects within the COMBINA function doesn’t matter.
COMBINA(n, k)
is equivalent toCOMBIN(n+k-1)
, which can be read as “(n+k-1)choose k” or.
COMBINA(n, k)
is also equivalent toFACT(n+k-1)/(FACT(k)*FACT(n-1))
, but supports larger numbers as arguments.- If a number (or reference to a number) with a decimal part is provided to COMBINA, the decimal part is silently truncated before calculation.
- If the some of arguments n+k is greater than or equal to 1031, a
#NUM!
error is returned.
Examples
In the following example with a pool of 2 objects (for example, A and B), there are 3 possible chosen combinations: (A, B), (A, A), and (B, B):
A | B |
---|---|
1 | Formula |
2 | =COMBINA(2, 2) |
In this example with a pool of 5 objects, there are 35 possible chosen combinations of 3 objects:
A | B |
---|---|
1 | Formula |
2 | =COMBINA(5, 3) |