Combinations...3

[mathdad]

Find the number of combinations of four names, Matthew, Ben, Greg, John, taken three at a time.

Let me see. I don't want to write each name over and over again.

Let M = Matthew, B = Ben, G = Greg, and J = John.

Combinations

{M, B, G,}, {M, G, J}, {M, B, J}, {B, G, J}

The book tells me that each combination consisting of three objects determines 3! = 3x 2 x 1 = 6 permutations of the three objects in the combination.

Here is my guess for the first combination, which is {M, B, G}:

MBG, MGB, BMG, GMV, GBM, BGM

I would need to do this for every combination.

You say?