Christopher T.

asked • 04/21/20

Probability of related events

I was presented with the following problem:

Choosing three cards from a deck of 52, what is the probability of getting 2 Kings and a Queen?


I had two thought processes that both led to different results:


1. (4 * 3 * 4) / 3! [3! to eliminate a set order caused by the multiplication] all over (52 3)


2. (4 2) (4 1) / 2! [2! to, again eliminate order] all over (52 3)


Checking with other online sources however, (4 2) (4 1) [without /2] is correct meaning that neither of mine are.


These answers are based on my observation that when multiplication occurs, such as in the problem of "choose a first place, second place, and third place," the answer is always: n(n-1)(n-2) this indicates a fixed order, so to remove this order, we divide by the (number of terms!), so can anyone explain why any of these is wrong, and why my observation does / does not make sense?

1 Expert Answer

By:

Raymond B. answered • 04/21/20

Tutor
5 (2)

Math, microeconomics or criminal justice

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