SOLUTION: I need the equation for figuring out how many mixtures (combinations) of letters can come from: ABCDE, then ABCDEF, then ABCDEFG, etc. (ex. for the first one ABCDE there are the fo

Algebra ->  Proportions  -> Lessons -> SOLUTION: I need the equation for figuring out how many mixtures (combinations) of letters can come from: ABCDE, then ABCDEF, then ABCDEFG, etc. (ex. for the first one ABCDE there are the fo      Log On


   



Question 92034: I need the equation for figuring out how many mixtures (combinations) of letters can come from: ABCDE, then ABCDEF, then ABCDEFG, etc. (ex. for the first one ABCDE there are the following mixtures: AB, AC, AD, AE, AF, ABC, ABD, ABE, ABDE, etc. but an equation would help me solve this much faster.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
nCr = n!/[(n-r)!r!]
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Example: for ABCDE
The # of combinations of 3 is 5C3 = 5!/[2!*3!] = [5*4*3/1*2*3] = 10
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Cheers,
Stan H.