Math (statics and probability) halp?

[Shaqo_Wyn]

Sup bruh's, my friendo needs help with a final math problem.

 

I used to be really good at this myself but the last time I had to do math was 5 years ago..

 

Problem:

You have a revolver with 6 chambers, you put three bullet in the chambers at random. What is the chance that the three bullets are next to each-other?

 

Thanks for your help in advance.

 

Shaqo

[givingtnt]

its simple, do the maths

 

4 diff possibilitys. with 6 diff positions. (4X6)+(3X6)+(2x6)+(1x6) =  60

                                                               24  +  18  +   12  +  6     =  60        so 6 in 60 chances of getting them all next to eachother

 

then take it, divide it by 6 (to get the smallest number)

 

around 1 in 10 chances to get all 3 next to eachother

[werto165]

edit forget that I was doing 6nCr3

 

Personally I think it's 3/10's 

[Mo5]

I think all you need to do is find all possible combinations first and then you divide the ways you enter them all next to each other with that.

 

4/20=0.2 -> 20%

 

I might be wrong.

[Guest]

^^ I got 1/5 (same thing). 

 

1 * 2/5 * 2/4 = 1/5 (I think thats right).

[Johannes_Lazor]

12,5% if my thinking is correct(But i doubt it since i have not worked with probablity in some time now).

100/2 = 50
50/2 = 25
25/2 = 12,5

[Me1z]

I think it's 3/10. Unless I missed something, there's 20 possible bullet configurations; 14 of which the 3 bullets are apart, and 6 of which the 3 bullets are together. 6/20 can be simplified to 3/10.

[_ASSASSIN_]

nop

[Shaqo_Wyn]

I think it's 3/10. Unless I missed something, there's 20 possible bullet configurations; 14 of which the 3 bullets are apart, and 6 of which the 3 bullets are together. 6/20 can be simplified to 3/10.

 

 

I think all you need to do is find all possible combinations first and then you divide the ways you enter them all next to each other with that.

 

4/20=0.2 -> 20%

 

I might be wrong.

 

 

edit forget that I was doing 6nCr3

 

Personally I think it's 3/10's 

 

 

its simple, do the maths

 

4 diff possibilitys. with 6 diff positions. (4X6)+(3X6)+(2x6)+(1x6) =  60

                                                               24  +  18  +   12  +  6     =  60        so 6 in 60 chances of getting them all next to eachother

 

then take it, divide it by 6 (to get the smallest number)

 

around 1 in 10 chances to get all 3 next to eachother

 

I agree that there are 6 options that they're next to each-other. 

 

But how'd you guys get to the amount of options that they aren't next to each-other.

[Me1z]

nop

 

[werto165]

I agree that there are 6 options that they're next to each-other. 

 

But how'd you guys get to the amount of options that they aren't next to each-other.

I think it could be 20 percent. 6/6*4/5*1/4 = 1/5 *100 = 20%

 

EDIT : NOPE. 

[Exp]

Edit: I couldn't do it algebraically without getting something that I know is wrong. I counted it out on paper and got 30% like the rest of you. I've been beaten, lol.

Edited March 8, 2015 by Exp

[Me1z]

I agree that there are 6 options that they're next to each-other. 

 

But how'd you guys get to the amount of options that they aren't next to each-other.

 

Simply put, I have too much free time. Ignore the bit I scribbled out.

 

[werto165]

Simply put, I have too much free time. Ignore the bit I scribbled out.

 

So we were all wrong? EDIT: nope it was correct 3/10... durr. 

 

I think I have the maths behind it: 

 

6 possible permutations(for bullets next to each other).

 

Using binomial expansion: 6nCr3

 

n! / ( r!(n - r)! )

 

6!/(3!(6-3)!) 

 

6!/(3!*3!) = 20 permuations in total.

 

6/20 = 3/10*100 = 30%

[Shaqo_Wyn]

Simply put, I have too much free time. Ignore the bit I scribbled out.

 

 

 

So we were all wrong? EDIT: nope it was correct 3/10... durr. 

 

We drew it too and also got 6/20. Used Pizza's.

[Shaqo_Wyn]

Thanks for your help mates. He's asking the teacher tomorrow, I'll let you guys know what the good answer was.

[werto165]

Thanks for your help mates. He's asking the teacher tomorrow, I'll let you guys know what the good answer was.

I'm pretty sure it's right, I did binomial expansion like 2 years ago for a week(AKA a day), I'm surprised that I actually remembered it. Binomial expansion can be a very handy tool when you're working out probabilities. I'll follow the topic and see if we were correct.