# code to write out combinations e.g. (10 choose 3)

#### Stellaferox

##### Active Member
Hi,

Related to my last question is the following. Does anyone have code to write out every possible combination (not permutation) from a given number X taken out Y (X choose Y)?
Any help appreciated. i just cannot seem to get the appropriate number written out.
Thx
Marc

#### derez

##### Expert
combination

http://en.wikipedia.org/wiki/Mathematical_combination

as an example - to choose 3 out of 10 you have :

10! / (3! * (10-3)!) = 3628800/(6*5040) = 120

(calculated by SCalculator , since the only code you need is Factorial function, you can find it there.)

#### derez

##### Expert
combination

Here is conceptual code, not debugged:
sub combination(x,y)
a = 1
for i = 1 to x
a = a*i
next
b = 1
for i = 1 to y
b=b*i
next
c=1
for i = 1 to x-y
c= c*i
next
return a/(b*c)
end sub

#### Stellaferox

##### Active Member
fill the a out of b and press go. you will get the number of combinations and the last one, and you can brouse up and down. 