-Homework Help! For Math ~ -

[kjSean]

if there are 9 ice cream flavors, and you can choose 3 from it to make a triple scoop combo, how many combinations are possible if you can get the same flavor twice or more? By the way, it says to use the nCr formula, not the nPr, because I am trying to get the COMBINATIONS, not the PERMUTATIONS.
Help??

By the way, it can be like Chocolate-Chocolate-Chocolate.

[azn4anime]

Why the hell would anyone get any other flavor then Chocolate-Chocolate-Chocolate?

stupidmathquestionisstupid

[Lore]

im gonna guess 729, just cause 9x9x9= 729, and im basing this off the fact that for each one you can have 9 different flavors, meaning say we number the flavors, it can be like this

1,1-9,1-9
2,1-9,1-9....
....
though if that true i have no idea, and i dont think thats how you want me to solve it.

[emailbox]

Easy.
9 nCr 3
=/

Combinations mean that the order of choices don't matter, and permutations is where the order matters (so 123 is different from 213).

I put it in my calculator, and it's 84.
Lore, you're wrong, because 9^3 would suggest that the order of the choices matters, which it does not.

[/data management]

[Lore]

knew i was wrong, thanks for explaining why though, i do not enjoy math

[zigkid3]

i dont think 9^3 makes the order. it just gives all possiblities.

if he did something like 9x8x7 then something like that would suggest you cant choose the same flavor but in this case you can.

so you get nine choices three times.

i dont know how your calculator even got 84 though.

but what can i say i havent done this in a long time xP

btw a4a youre wrong, its vanilla-vanilla-vanilla

[LT gamer]

Zig here's how: nCr=n!/((n-r)!(r!)

Let n=9, and r=3. Voila.

[emailbox]

Zig here's how: nCr=n!/((n-r)!(r!)

Let n=9, and r=3. Voila.

Yup. The calculator does it for you.
Where n is the number of total choices
r is the number you can choose
! is factorial, meaning (n)(n-1)(n-2)...(3)(2)(1)

[nighthawk911]

What class is this again?

[LT gamer]

Err, it might be stats. But I remember learning this in Algebra 2.