So I'd like to know how to "compute" the Probability of the following:

Choose 3, values must add up to 7.

1, 1, 5

1, 5, 1

5, 1, 1

1, 2, 4

1, 4, 2

4, 1, 2

4, 2, 1

2, 4, 1

2, 1, 4

etc.

My problem is how to compute for the TOTAL... If you can explain it too. That would be great. Because I am unsure about the TOTAL. It was 9 and that may be too high and 6 was too low... 7 seems to be a bit more than the 6 ... But I'd like to know how many possibilities exist.

Is this even possible to compute, IDK?!

One of you PRO mathematicians (I know we've got a few of them around!), my great gratitude if you can help me with the formula.

Also is there anywhere where I can get ALL the possibilities??? Some kind of website, maybe?!

Cheers.

Let's say my total is "9":

And this has allowed my to compute for 8, 7 or 6 also. That's how you do it "MANUALLY"... Anyhow 9 was tops and has the most amount of choices.