[tuckerlk]

I need help with these questions, I just can't seem to get them right.

1. Separate the 12 face cards from the rest of the deck. Assume that the remaining cards have been shuffled. Select THREE cards from the pile of face cards (i.e. 3 jacks, 3 queens, or 3 kings) from the pile?


2. Separate the 12 face cards from the rest of the deck. Assume that the remaining cards have been shuffled. How many ways are there of selecting one of each face card from the pile?

[asterisk_man]

Just to be clear, you're removing 12 face cards and then selecting cards from that pile of 12?

[tuckerlk]

Yes that is correct

[asterisk_man]

Ok, just to begin lets enumerate the 12 cards in our pile. I'll use JQK for the values and SDHC for the suits (hopefully obvious)
We've got: JS JD JH JC QS QD QH QC KS KD KH KC
Now, for problem 1:
What is the probability that if we select 3 cards they will all have the same value? Since the suits don't matter we have JJJJQQQQKKKK, the probability will be 3 times the probability of picking a specific value three times. P(selecting 3 J)=P(selecting J 1st)*P(selecting J 2nd)*P(selecting J 3rd)=4/12*3/11*2/10=1/55 so P(selecting 3 of the same)=3*P(selecting 3 J)=3/55

I assume you want the probability of selecting 3 of the same suit. There are obviously 3*(4 choose 3) = 12 ways to do that.

For problem 2:
So we want to select 3 cards and get 1 of each value. Think of it like this: There are 4 ways to pick 1 J, then for each of those 4 ways there are 4 ways to add 1 Q, so that's 4*4=16. Then for each of those 16 ways there are 4 ways to add 1 K so that's 16*4=64.

Someone might come by and give you some stock probability answer but I like doing it the hard way!

[tuckerlk]

Are you any good with geomtry? I can't seem to attach the files to ask for help

[asterisk_man]

Please ask your geometry questions. If I can't field them someone else surely can. If you try to describe your problem someone might likely create an image to clarify.