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# Probability of rolling a dice.

Hoping someone can help me figure this out, was trying to work this out with my father in law last night.

Basically what's the probability of rolling a 1 on a dice? 1/6 surely?

Therefore what's the probability of rolling a 1 on a dice if you roll it 6 times? I said it was 1/1 but as he quite rightly pointed out that would be a certainty and it's not a certainty. The only way I can think to explain it is that it is all based on averages, ie if you roll it 6 times then on average you would get a 1 once which would be 1/1 wouldn't it???

Basically what's the probability of rolling a 1 on a dice? 1/6 surely?

Therefore what's the probability of rolling a 1 on a dice if you roll it 6 times? I said it was 1/1 but as he quite rightly pointed out that would be a certainty and it's not a certainty. The only way I can think to explain it is that it is all based on averages, ie if you roll it 6 times then on average you would get a 1 once which would be 1/1 wouldn't it???

1/6 means you've got one chance in 6 of getting the number. theres 6 numbers on the die, so EVERY number is 1/6

Original Poster

I mean getting a 1 somewhere on your six throws.

So you throw six times and therefore will get six numbers, what's the probability of one of those being a 1?

Which would mean you'd get a 1 every 46656 times?:roll:

Original Poster

Are you sure?

So if I ran this experiment 46656 times then I would only get a 1 once???

do it and we will see, lol :thumbsup:

There you go,

told you I was right :thumbsup: *cheeky smile*

Original Poster

That part's easy!!! That's for rolling the dice ONCE!

They were unsuccessfull 5 times.

Successful once.

Original Poster

he doesn't mean in a row.

No, that means in 6 rolls you'd get a 1 six times.

If you roll it 6 times you have a 6/36 chance of rolling a 6.

Original Poster

So as a whole it happened 1 time out of one? See my point?

It's the same.

Throw 1 dice = 1/6 chance of getting it = 1/6

Throw 2 dice = 2/12 chance of getting it = 1/6

Throw 3 dice = 3/18 chance of getting it = 1/6

etc.

o ok... so whats the question??!?

Original Poster

I'm talking about as a whole.

It's 1/6.

1/6 x 5/6 x 5/6 x 5/6 x 5/6 x 5/6 = 3125/46656 = 0.6698

5/6 = chance of not getting a 1

1/6 = chance of getting a 1

See, this is where you just threw me out the plane..

Original Poster

So if I threw a dice one thousand times then the probability of getting at least one 1 would be 1/6? Surely not??? I would be virtually guarenteed to get a one somewhere!

Nope, it's still 1/6. You are assuming that what you have thrown before affects the next throw - it doesn't.

If you toss a coin 999 times and get heads each time, the chances of getting tails on the next occasion is still 1/2.

:thumbsup:

:thumbsup:

Wrong, that is the probabilty of one outcome on one die!:oops:

The probability of throwing a number on single die is 1 in 6 not as in this case 6 throws so all you saying 1/6 are wrong.

Original Poster

I'm not talking about the next occasion, I'm talking about one of the throws resulting in a 1. To use your example if you tossed the coin 999 times then you surely would be virtually guarnenteed to have got a head?

I thought passing maths at GCSE was the end of using numbers! Obviously not!

Wrong

Wrong

If you roll a dice 6 times but only get a 1 once then these are the results:

1/6 x 5/6 x 5/6 x 5/6 x 5/6 x 5/6 = 3125/46656 = 0.6698

5/6 = chance of not getting a 1

1/6 = chance of getting a 1

and yes its right Im the king of maths...

Original Poster

Thanks, I know that! What's the right answer????

So you've got a less then one chance of getting a one? o.O

Also wrong, that is the probability of throwing a 1 on 1 die but if you don't throw a 1 on 5 dice, then on the 6th this is 1 in 6. In this scenario, you have calculated the probabilty of throwing a 1 only once in 6 throws

Original Poster

Isn't it 1/6 x 6/6 x 6/6 x 6/6 x 6/6 x 6/6? ie 1/1.

Because the others don't matter, as long as one is 1/6?