I need help with a few math problems (probability) - Got the help - thanks -

[badluck]

If you answer the 3 questions correctly, I will give you $3 PayPal for helping me! I need the info on how you got the answer, not just the answer (so I can learn this stuff).

It's not really homework, but I have this test I'm studying for and I can't figure out these "helper" problems. I can't go visit the math tutors cuz I'm so damn busy with work and school and they don't have spots open....ugghhh....can anybody PM me who is good with math problems that deal with probability? Thanks so much....I hate my life.


Question: Suppose you are dealt a hand of 3 cards out of a stack of 12 face cards (king, queen, and jack). How many possible combinations of the 12 face cards taken 3 at a time can there be?

Answer: 220 (I got this one right)


Here are the problems that I need help with. I gave you the first problem because the problems that follow are a continuation of the problem above:

-------------------
Problems:
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How many different combinations can there be, such that, you will be dealt exactly two kings?
------------------------------
What is the probability that you will be dealt exactly two kings out of the 3 cards you are dealt?
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Suppose you are dealt such a hand of 3 cards twice. What is the probability that you will receive exacly 2 kings in each of the two deals?

 

[Analog]

Methinks the probability of having these problems solved here are low.

 

[badluck]

come on.....this is a forum where nerds come together and unite!!!!

help!!!!!!!!!!!!!!!!!

 

Your nick is prophetic.

 

[badluck]

okay, $3 PayPal to the 1st person who gets the answers correct.....heh.

 

[cloude27]

this is making my head hurt

 

[caitlion]

explain how you got the first answer.. i forget how to do probability stuff, but it might help me remember?

 

[Need4Speed]

do your own damn homework

 

[badluck]

do your own damn homework

read the thread and quit trolling.



Here is how I did the 1st problem:


12C3 = 12!/(12-3!) * 3! = 12!/9!*3! = 220

 

[caitlion]

hahah, nevermind. sorry but i dont even know what the ! are for good luck though.

 

[TooOne21]

Uh. I got my degree... Not in math though... have fun!

 

[badluck]

damn, damn, damn!! LOL.....

 

[Kyteland]

OK, I'll help you out. First off let me say that these questions are really easy probability questions and if you don't understand how to get the answers you need to study more for your test.

Question: Suppose you are dealt a hand of 3 cards out of a stack of 12 face cards (king, queen, and jack). How many possible combinations of the 12 face cards taken 3 at a time can there be?

Answer: 220 (I got this one right)

12C3=220
That's right. There are 12 objects to choose from and you need to arbitrarily choose 3 of them.

How many different combinations can there be, such that, you will be dealt exactly two kings?

This question is asking, out of those 220 possible hands, how many of those have 2 kings in them. You have 4 kings and you need to arbitrarily choose 2 of them. 4C2=6. You have 1 card left and it needs to be either a queen or a jack. Since there are 8 of those you need to choose 1 of the 8. 8C1=8. 6*8=48

(4C2)*(8C1)=48
There are 48 hands with exactly 2 kings

What is the probability that you will be dealt exactly two kings out of the 3 cards you are dealt?

What is the definition of probability? It is the number of desired outcomes / the number of possible outcomes. You already calculated both of these in the previous questions so just plug them in to the equation.

probability = 48/220 = .2181818181...

Suppose you are dealt such a hand of 3 cards twice. What is the probability that you will receive exacly 2 kings in each of the two deals?

This question is a little ambiguous. I'll assume that it means to deal a hand from the 12 and then shuffle all the cards and deal another hand from 12. You already know the probability of it hapening once (48/220) so the probability of it happening twice is (48/220)^2 = (48/220)/(48/220) = (2304/48400) = .0476033057...

It could also mean that you deal a hand of 3 from the 12 and then a hand of 3 from the remaining 9. The answer to that is (336/18480) = .0181818.. but I'll let you figure out how I got that.

 

[abracadabra1]

nice work Kyteland

I don't know nothing about probability/statistics...but I think it's pretty interesting stuff.

 

[upsciLLion]

Kyteland nailed it right on the head. Probability is the second coolest type of mathematics next to calculus.

I <3 math

ups

 

[badluck]

I sent Kyteland a message saying thanks! Just wanted to post it on here as well.

Thanks Kyteland!!!

 

[Kyteland]

Originally posted by: upsciLLion
Kyteland nailed it right on the head. Probability is the second coolest type of mathematics next to calculus.

I <3 math

ups

Yeah, I try to answer math questions on here when I can. I do this stuff for a living so it isn't really hard for me to do. I get to do math/probability every day for a slot machine manufacturer, and it is a great job.

Badluck, I don't have paypal so don't worry about it. If you have questions don't hesitate to ask.