Tracking all combinations

Hi:

Try looking here for some help

http://www.mrexcel.com/board2/viewtopic.php?t=49774&highlight=combinations


plettieri

Hi! Plettieri,

I think that scenerio is different where there were three columns. But I have only one column and 10 rows.

Maxi

I would also like to know how many possibilities (Groups) can be created from the given data.

Thanx
Maxi

I think I am not clear with my question

For example:

If I have five workers "A", "B", "C", "D" & "E" and if I want to create groups or two workers each, then there would be 10 possibilities:

AB, AC, AD, AE, BC, BD, BE, CD, CE & DE

Now If I have ten workers "A", "B", "C", "D", "E", "F", "G", "H", "I", "J" and "K" and if I want to create groups. Each group will consist of 4 workers. Every worker should get an opportunity to work with all the other workers.

How many possiblities would get created and how?

Maxi

"How many possiblities would get created and how?"

You need to use factorials. See also for example:
http://www.glencoe.com/sec/math/algebra/algebra1/algebra1_03/extra_examples/chapter14/lesson14_2.pdf

So the answer reduces to 10!/(6!x4!)
i.e. 10x9x8x7 divided by 4x3x2x1 = 210

Hi:


You might try this code taken from an earlier post (Jay Petrulus), I am not sure you can do this easily with formulas...

Sub Combinations()
Dim n As Integer, m As Integer, numcomb
numcomb = 0
n = InputBox("Number of items?", "Combinations")
m = InputBox("Taken how many at a time?", "Combinations")
Application.ScreenUpdating = False
Comb2 n, m, 1, ""
End Sub

'Generate combinations of integers k..n taken m at a time, recursively
Private Function Comb2(ByVal n As Integer, ByVal m As Integer, _
ByVal k As Integer, ByVal s As String)
If m > n - k + 1 Then Exit Function
If m = 0 Then
ActiveCell = s
ActiveCell.Offset(1, 0).Select
Exit Function
End If
Comb2 n, m - 1, k + 1, s & k & " "
Comb2 n, m, k + 1, s
End Function


I quickly tested the resultes and on 10 possible and selecting 4 I obtained a combination of 210 possible...I believe that is correct combinations.

hope this helps
plettieri

Hi:

Just a footnote on how to get the total required

=COMBIN(10,4) equals the 210 required.

plettieri

" I am not sure you can do this easily with formulas... "

Very right. Excel won't calculate above factorial 170

Thats gr8. It worked. Thanx a million !!!

Maxi