Permutation creations on excel

**jaheimando** · 02-17-2010, 08:53 AM

Hello, I would like some in calculating several combinations. for example
There are 7 Class rooms with 9 students in each, I want to pick 1 from each and make a group of 7, but I want to know of all the possible combinations of seven students that I can pick out of the 7 classrooms that I can have and I want this to displayed in excel, what would be the formula in creating the combinations. Thank you

example of class and students

class A1 class B2 class C3 class D4 class E5 class F6 classG7
studentA1 student B1 etc.. etc etc etc etcc
studentA2 student B2
studentA3 studentb3
studentA4 etc...
studentA5
studentA6
studentA7
studentA8
studentA9

**shg** · 02-17-2010, 12:11 PM

There are 9^7 ~ 5M combinations, requiring a 20MB spreadsheet. What would you do after you listed them?

**jaheimando** · 02-17-2010, 02:09 PM

so does that equate to 9x9x9x9 etcc by 7....I understand this now and it will require high numbers. I guess what I need to know is how to create these combinations on excel even if I work with smaller numbers i.e 5x5x5 etcc, can you teach me the formula please ? I am currently studing a statistics based module that is why it os useful for me to learn.
Thanks

**shg** · 02-17-2010, 02:13 PM

See, for example, http://www.excelforum.com/excel-work...n-formula.html

**jaheimando** · 02-17-2010, 02:40 PM

Thank you, so do I just apply the same formula to which ever combination style I use for the '***' & 'count' boxes ?

**shg** · 02-17-2010, 02:44 PM

Just copy all the formulas across, yes.

**jaheimando** · 02-18-2010, 08:54 AM

Hello, I have uploaded an excel file with the copied formula, however I'm having trouble with the 'count formula' can you please check it as I have different amount of numbers compared to the example you showed me earlier, what do I have to change on the formula ? Thank you