Hey Veeky Forums, I'm shit at math so I was hoping you guys could help me grasp probability. I contrived a word problem but have no idea how to solve it.
> Guy A asks Guy B to guess a 3-letter acronym, what is the mathematical likelihood Guy B will guess all letters correctly in order? What about out of order? Guy A tells him the first letter, what would the probability be now?
Even to me it's obvious if it was just 1 letter it would be 1/26, but what about 2? Is that 26x26? What about 3 or 4 letters, and so on? Are there x-factors, do they stack?
Nicholas Baker
*buhuuurp* Just lick my balls, Mharti
Ethan Myers
Weed need to go *buuuuurp* back to *baarp* da future.
Thomas Jenkins
How many letters does the alphabet have which the guy is using to create this acronym?
Out of order you have combinations with order you have permutations.
Caleb Cooper
>Guy A asks Guy B to guess a 3-letter acronym, what is the mathematical likelihood Guy B will guess all letters correctly in order?
Let's say the acronym is ABC. The chance of guessing A first is 1/26, B second is 1/26, and C third is 1/26. If you multiply them together, (1/26)^3 is 1/17576.
>What about out of order? Now, there are 6 possible orientations of ABC, which are: ABC, ACB, CAB, CBA, BAC, and BCA (this can be calculated using 3!). Since there are 6 times more orientations, you multiply 1/17576 from the answer by 6.
>Guy A tells him the first letter, what would the probability be now? Since A is a given, and order still matters, the probability of guessing B and C in order are both 1/26. So, (1/26)^2 is 676.
Ryan Rogers
Assuming no extra information like what combinations that are not acronyms:
For each letter space in the acronym there are 26 possible combinations so in total there are 26*26*26 possible 3 letter combinations,which would be 17576.
To guess them in order that means that he would need to fine the single one combination that matches the acronym guy A is talking about so 1/17576
To guess them out order he would simply need to find the three letters and order in one of the possible ways, which would be 3 factorial or six. Therefore to guess it out of order the chances are 6/17576
If the guy is told the first letter then in order it would be 1/676 and to get them in any order it would be 2 factorial out of 676 so 2/676
ez pz. From the way I've laid it out you can probably generalize on your own.
Dylan Richardson
Thanks for the help, Veeky Forums
Is Doc and Mharti scientifically accurate?
> like what combinations that are not acronyms What does this mean? And why did you use the factorial?
James Hernandez
>What does this mean?
Well, maybe a problem will have rules as to what constitutes a proper acronym. Imagine if the problem were to be about words. 'bow' is a 3 letter word but 'wwz' is not a 3 letter word, as it is not even a word. In the problem I am just assuming that there are no rules that limit the possibilities.
>And why did you use the factorial?
Because imagine if the acronym is XYZ. To get these out of order correctly you could guess YZX or YXZ, etc. Those are 3 letters so you want to find out how many ways are there to 'order' three obejcts, and that is exactly what the factorial defined over the naturals does.
It is just a function. You could also find all the combinations by hand but why do that when mathematicians already solved this problem.
Joseph Myers
number of possible desired outcomes / number of all outcomes
how many different ways are there to pick 3 letters from 26
ordered -> 26 P 3
unordered -> 26 C 3
so the probability of picking a winning premutation is 1/(26 P 3)
fuck combinations though
Adrian Sanders
Your shit is as bad as those pedophile cartoons. Fucking degenerate
