# Combinations Question

• Feb 25th 2010, 10:13 AM
applewine
Combinations Question
I have required fields to fill in before somebody clicks submit in a computer program, but I want to tell our testing team that we need to test to make sure the program does not submit unless all required fields are filled in. But, I want to test all of the combinations of the required fields, except for the combination where I fill all the fields in because that should always work.

Is this expressed as

If so, do you know if there is any software program we could use that will generate a true/false table of combinations if we supply the names of the variables to automate a list for us so that this can be printed out? It would have to be something free, but I just need a basic program.

Thanks
• Feb 25th 2010, 10:54 AM
Hello applewine

Welcome to Math Help Forum!
Quote:

Originally Posted by applewine
I have required fields to fill in before somebody clicks submit in a computer program, but I want to tell our testing team that we need to test to make sure the program does not submit unless all required fields are filled in. But, I want to test all of the combinations of the required fields, except for the combination where I fill all the fields in because that should always work.

Is this expressed as

No. This assumes that all the required fields are filled in except 1. You need to test for $0, 1, ..., (n-1)$ fields filled in. The total number of possibilities is therefore
$\sum_{i=0}^{n-1}\binom ni = 2^n -1$