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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???

no, its 1/6 for every number, if it was 1/1 you'd get 1 on every roll.

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

nope it would be 1/6 x 1/6 x 1/6 x 1/6 x 1/6 x 1/6 = 1/ 46656

u ADDED 1/6 6 times making it 1/1

Original Poster

t0mm;1687665

no, its 1/6 for every number, if it was 1/1 you'd get 1 on every roll.1/6 … no, its 1/6 for every number, if it was 1/1 you'd get 1 on every roll.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

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?

faiza1;1687670

nope it would be 1/6 x 1/6 x 1/6 x 1/6 x 1/6 x 1/6 = 1/ 46656

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

1/6

Original Poster

faiza1;1687670

nope it would be 1/6 x 1/6 x 1/6 x 1/6 x 1/6 x 1/6 = 1/ 46656

Are you sure?

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

Benjimoron;1687691

Are you sure?So if I ran this experiment 46656 times then I would only … 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:

You need to do a tree diagram, I would but I forgot him to do them :|, there not hard to do either, take about 5mins

Original Poster

t0mm;1687705

http://www.knowyourluck.com/dice1.htmlThere you go,told you I was right … http://www.knowyourluck.com/dice1.htmlThere you go,told you I was right :thumbsup: *cheeky smile*

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

the probability of rolling a 1 six times in a row would be 1/46656

nononono that's for rolling it 6 times.

They were unsuccessfull 5 times.
Successful once.

Original Poster

Is the answer 6/6 but bare in mind it's an average not a certainty?

its simple maths guys!!!

faiza1;1687718

the probability of rolling a 1 six times in a row would be 1/46656

he doesn't mean in a row.

Benjimoron;1687720

Is the answer 6/6 but bare in mind it's an average not a certainty?

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

In each throw you have a 1/6 chance of rolling a 6.

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

Original Poster

t0mm;1687719

nononono that's for rolling it 6 times.They were unsuccessfull 5 … nononono that's for rolling it 6 times.They were unsuccessfull 5 times.Successful once.

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

Benjimoron;1687713

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

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.

t0mm;1687725

he doesn't mean in a row.

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

Original Poster

t0mm;1687727

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

I'm talking about as a whole.

If he rolls a dice six times what's the chance of getting a 1 once
It's 1/6.

If you roll a dice 6 times but only get a 1 once then this is 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

Benjimoron;1687749

I'm talking about as a whole.

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

ohhhhh i get it!

Original Poster

nightswimmer;1687745

It's the same. Throw 1 dice = 1/6 chance of getting it = 1/6Throw 2 dice … It's the same. Throw 1 dice = 1/6 chance of getting it = 1/6Throw 2 dice = 2/12 chance of getting it = 1/6Throw 3 dice = 3/18 chance of getting it = 1/6etc.

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!

Benjimoron;1687760

So if I threw a dice one thousand times then the probability of getting … 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.

BillButter;1687752

If you roll a dice 6 times but only get a 1 once then this is the … If you roll a dice 6 times but only get a 1 once then this is the results:1/6 x 5/6 x 5/6 x 5/6 x 5/6 x 5/6 = 3125/46656 = 0.66985/6 = chance of not getting a 11/6 = chance of getting a 1

:thumbsup:

nightswimmer;1687763

Nope, it's still 1/6. You are assuming that what you have thrown before … 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:

Benjimoron;1687713

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

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

nightswimmer;1687763

Nope, it's still 1/6. You are assuming that what you have thrown before … 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.

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?

If you throw a dice six times the probability is 1 in 6 [because the other 5 can be 2,3,4,5,6]

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

TheDoc;1687728

In each throw you have a 1/6 chance of rolling a 6.If you roll it 6 times … In each throw you have a 1/6 chance of rolling a 6.If you roll it 6 times you have a 6/36 chance of rolling a 6.

Wrong

nightswimmer;1687745

It's the same. Throw 1 dice = 1/6 chance of getting it = 1/6Throw 2 dice … It's the same. Throw 1 dice = 1/6 chance of getting it = 1/6Throw 2 dice = 2/12 chance of getting it = 1/6Throw 3 dice = 3/18 chance of getting it = 1/6etc.

Wrong

Just incase nobody saw the first time:

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

warmapplepie;1687797

Wrong

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

BillButter;1687798

Just incase nobody saw the first time:If you roll a dice 6 times but only … Just incase nobody saw the first time: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 = 0.66985/6 = chance of not getting a 11/6 = chance of getting a 1and yes its right Im the king of maths...

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

BillButter;1687752

If you roll a dice 6 times but only get a 1 once then this is the … If you roll a dice 6 times but only get a 1 once then this is the results:1/6 x 5/6 x 5/6 x 5/6 x 5/6 x 5/6 = 3125/46656 = 0.66985/6 = chance of not getting a 11/6 = chance of getting a 1

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

BillButter;1687798

Just incase nobody saw the first time:If you roll a dice 6 times but only … Just incase nobody saw the first time: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 = 0.66985/6 = chance of not getting a 11/6 = chance of getting a 1and yes its right Im the king of maths...

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?