The COMBIN function returns the number of different ways you can combine a number of items into groups of a specific size, ignoring the order within the groups. Both arguments are number values.
COMBIN(total-items, group-size)
total-items: The total number of items. total-items must be greater than or equal to 0. Any decimal part of total-items is ignored.
group-size: The number of items combined in each group. group-size must be greater than or equal to 0. Any decimal part is ignored.
Notes
Combinations are not the same as permutations. The order of the items in a group is ignored for combinations but not for permutations. For example, (1, 2, 3) and (3, 2, 1) are the same combination but are different permutations. If you want the number of permutations, use the PERMUT function.
Examples |
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=COMBIN(3, 2) returns 3, the number of unique groups you can create if you start with 3 items and group them 2 at a time. For example, if the group consisted of 1, 2, and 4, the possible unique groups are: 1 and 2, 1 and 4, 2 and 4. =COMBIN(3.2, 2.3) returns 3. Fractional parts are dropped. =COMBIN(5, 2) and =COMBIN(5, 3) both return 10. |