# QR Probability and stats

#### csulapredental

anyone know an efficient way on knowing if something is gonna use the combination formula or the permutation.. not order matters or it doesn't cuz that don't work. something accurate

like for example: how many ways can 8 horses Finnish a race in first second and third place. - permutation

or there are 12 members of the democratic party at a meeting, how any diff groups of 3 can be formed - combination

whhhhY

#### Plum_489

Do you have Chad's videos? I struggled with this when I was studying for the DAT, but his explanation helped me visualize and understand them a little better!

OP
C

#### csulapredental

Do you have Chad's videos? I struggled with this when I was studying for the DAT, but his explanation helped me visualize and understand them a little better!
I DO but he does it in a way where u don't use the equation and it takes thinking.
id rather just plug that shiz in and move on u feel me?

#### Plum_489

I DO but he does it in a way where u don't use the equation and it takes thinking.
id rather just plug that shiz in and move on u feel me?
I feel you on that. For me it was easier than trying to memorize an equation. Sorry I can't help you with the equations good luck with it though!

#### Roy Williams

2+ Year Member
You won't get these questions on the DAT. I would spend more time on central tendency which is the current trend now on the real deal like some of the experts out there say. There are some good practice on Destroyer and Achiever that you can also choose to practice else where, books , Google etc
Not sure how you can state this with such confidence... Be careful OP, you very well may get a question like this.

For the first one, order matters since it's the order of a race. So you'd use the permutation formula, n! / (n-k)!

For the second one think about it like "how many possible ways can i choose 3 people from a group of 12". So that would be 12 Choose 3. n! / k!(n-k)! = 12!/(3!*9!)

#### roy williams II

2+ Year Member
I'm having the same problem!! I hate probability and permutations/combinations!

#### DMikes

2+ Year Member
You can definitely have these questions on the DAT. No idea why @JSurey is claiming otherwise.

Does it matter if you take 1st, 2nd, or 3rd in some sort of contest or competition? YES. Does it matter if you are simply the "second" member of a group vs being the "third?" NO. The simplest explanation really is, "does order matter" or "does placement matter?"

Perhaps Chad has a better explanation; I didn't watch his QR videos. But to me, that is far and away the simplest way to look at it.

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