a math question

[Invader Bugs]

can someone help me with this? its not homework or anything, someone asked me and i want to figure it out.

A deck of cards contains 16 black cards and 4 red cards. (there are 20 cards)
What is the probability of getting all 4 red cards if you randomly choose 4 cards from the deck?

[Davey Rootbeer]

well,.. it's a simple combination problem thingy, i think.

There's a 4 in 20 chance of getting it on thre first draw. and the second draw, there's a 3 out of 19 chance. third, 2 out of 18, and 4th, 1 out of 17.

(that's if you don't replace them back into the deck! you didn't really specify that, so i'm assuming...)

so 20x19x18x17= 116280

and since there's 4 cards, it would be over 4x3x2x1= 24

116280/24=4845, or ₂₀C₄ which is 1 in 4845.

Unless i just got it completely wrong. I haven't taken this kind of math in about 5 years.

[Invader Bugs]

nope, you were right. thanks and congrats.

[rocketgal]

but what did you LEARN

[SLUM WIZZARD]

...He learned to always ask Davey his math problems because he is good at math?

[Davey Rootbeer]

...He learned to always ask Davey his math problems because he is good at math?


hey, free experience points for me, buddy.

It's always nice to have someone fight your battles for you, until you meet that one boss you just can't kill ,because your levels are low from always having been helped.

~From "Everything in life is exactly like and can be linked to an RPG", Random House, 1996.

[leatherface]

I wish that was a real book, I'd give my working organs for it.