# Who's good with probability?

Found 30th Oct 2008
I thought of something this morning whilst snoozing my alarm...

If you play the National Lottery and pick the same numbers each week, do you have a greater probability each week of winning? I'm trying to remember back to what I was taught at school but its all a blur!

Surely if, for example, number 6 doesn't come up this week, there is an ever so slightly greater chance it will come up next week, and again the following week etc.

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No the probability of any number coming up is exactly the same. So 6 numbers that won last week has the same probability as this week.

Original Poster

Ooh. Thats that then! Just in my head it would make sense. Like if you are rolling a dice, it gets more and more likely that the next roll will be a 4.....

KINGROBTHEFIRST;3324278

No the probability of any number coming up is exactly the same. So 6 … No the probability of any number coming up is exactly the same. So 6 numbers that won last week has the same probability as this week.

WHITCH MAKES YOU REALISE THE PROBABLE CHANCE OF WINNING IS PROBABLY NOT WORTH DOING,PROBABLY:):oops:

03bintls;3324304

Ooh. Thats that then! Just in my head it would make sense. Like if you … Ooh. Thats that then! Just in my head it would make sense. Like if you are rolling a dice, it gets more and more likely that the next roll will be a 4.....

Here's a quick example.....

6 numbers on a dice.....

the probability of 1 coming up is 1 in 6

1st roll: 1
2nd roll: 1
3rd roll: 1
4th roll: 1
5th roll: 1

for the 6th roll you must be thinking got to be 2,3,4,5 or 6 but any number still has a 1 in 6 chance of coming up including the 1 again.

Think roulette.......red or black, if red came up 24 times in a row you'd be thinking got to be black next but its still a 1 in 2 chance, same as red again.

It's possible that the winning numbers could just as easily be a sequence (i.e. "1,2,3,4,5,6") as any 6 numbers. The probability of this happening, though, is not so great, due to the effects of randomness.

That's the difference between 'possible' & 'probable'.

(Did you know that you can predict randomness? I had to study this as part of a course - all I could hear was a whooshing sound, as everything was flying well over my head :-D)

Original Poster

I seeeeee! I'm clearly getting confused with something that isn't classed as probability! All very confusing this subject - never again will I begin thinking so early in a morning!

Banned

03bintls;3324381

I seeeeee! I'm clearly getting confused with something that isn't classed … I seeeeee! I'm clearly getting confused with something that isn't classed as probability! All very confusing this subject - never again will I begin thinking so early in a morning!

I try and do it as less as possible and rely on instinct...

makes the world a better place

ODB_69;3324412

I try and do it as less as possible and rely on instinct...

That seems to work for my wife :thumbsup: . Every time we go to a casino I am good with numbers so I go by probability, she goes by instinct.

Guess who wins most of the time. You were quite right she does. Between the two at least we broke even :oops:

well ure probability will remain the same!! It would increase/decrease if the two draws were not exlclusive... or lets say, they removed the iwnning numbers from the balls for the next draw, then the probability of your numbers coming up increases!!

Lets take a example, if only 1 number is selected. You chose 3, your probability of winning between 0-9 is 1/10

lets say a draw is done, and it draws 2. Now you have two possibilities.
If the ball is then put back into the pool of balls for another draw, then the probability is back to 1/10
But if the ball is removed from the draw, your probability increases to 1/9 as only 9 balls are left.

and so on!!

In a casino, if you are playing Blackjack, you can use this principle to guess or predict the crads left in the deck, as everytime you play a hand, the cards are removed from the deck. Thus if your hand as all low numbers, your probability of higher value cards in the next hand increases.

Hope it helps

job for Actuarial Science students lol, if only they won a lottery!

KINGROBTHEFIRST;3324333

Think roulette.......red or black, if red came up 24 times in a row you'd … Think roulette.......red or black, if red came up 24 times in a row you'd be thinking got to be black next but its still a 1 in 2 chance, same as red again.

Don't forget that nasty green zero in there. :x

I still say the probability of winning the lottery is 50:50.
You either win or you don't. :w00t:

save up your weekly entries and do one big one - say every year. That would increase the chances (by a small amount)

Choose a big rollover week as well.

Make a note of my email address and send me a share.

Half will be fine - I'm not a greedy person.

we did a pretty cool probabilty question in maths, see if you can get it,

Suppose you're on a game show and you're given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. The rules of the game show are as follows: After you have chosen a door, the door remains closed for the time being. The game show host, Monty Hall, who knows what is behind the doors, now has to open one of the two remaining doors, and the door he opens must have a goat behind it. If both remaining doors have goats behind them, he chooses one randomly. After Monty Hall opens a door with a goat, he will ask you to decide whether you want to stay with your first choice or to switch to the last remaining door. Imagine that you chose Door 1 and the host opens Door 3, which has a goat. He then asks you "Do you want to switch to Door Number 2?" Is it to your advantage to change your choice?

give it some thought, it will suprise you.

To all those that have never won the lottery try this.

You are obviously picking the wrong numbers every week.

Instead of 6 pick 43 numbers as you are brilliant at picking numbers that do not win (probably been picking the wrong numbers since it started haven't you)

Put your money on the 6 numers left, these should be the winning ones if your past record is anything to go by.

wazb;3325287

we did a pretty cool probabilty question in maths, see if you can get … we did a pretty cool probabilty question in maths, see if you can get it,Suppose you're on a game show and you're given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. The rules of the game show are as follows: After you have chosen a door, the door remains closed for the time being. The game show host, Monty Hall, who knows what is behind the doors, now has to open one of the two remaining doors, and the door he opens must have a goat behind it. If both remaining doors have goats behind them, he chooses one randomly. After Monty Hall opens a door with a goat, he will ask you to decide whether you want to stay with your first choice or to switch to the last remaining door. Imagine that you chose Door 1 and the host opens Door 3, which has a goat. He then asks you "Do you want to switch to Door Number 2?" Is it to your advantage to change your choice? give it some thought, it will suprise you.

I've seen this before.
It's quite amazing. :thumbsup:

03bintls;3324304

Ooh. Thats that then! Just in my head it would make sense. Like if you … Ooh. Thats that then! Just in my head it would make sense. Like if you are rolling a dice, it gets more and more likely that the next roll will be a 4.....

Not read through whole thread but this isn't correct. Same odds every time you roll the dice.

Banned

wazb;3325287

we did a pretty cool probabilty question in maths, see if you can get … we did a pretty cool probabilty question in maths, see if you can get it,Suppose you're on a game show and you're given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. The rules of the game show are as follows: After you have chosen a door, the door remains closed for the time being. The game show host, Monty Hall, who knows what is behind the doors, now has to open one of the two remaining doors, and the door he opens must have a goat behind it. If both remaining doors have goats behind them, he chooses one randomly. After Monty Hall opens a door with a goat, he will ask you to decide whether you want to stay with your first choice or to switch to the last remaining door. Imagine that you chose Door 1 and the host opens Door 3, which has a goat. He then asks you "Do you want to switch to Door Number 2?" Is it to your advantage to change your choice? give it some thought, it will suprise you.

Better to switch as you originally had a 1 in 3 chance of picking the car leaving monty with a 2 in 3 chance of picking the car. Then monty has to eliminate a door with a goat.

Banned

Jumpingphil;3332890

If anyone is really … If anyone is really interested.http://www.grand-illusions.com/articles/monty_hall/

Just noticed this!

Honest Guv :thumbsup:

KINGROBTHEFIRST;3324333

Here's a quick example.....6 numbers on a dice.....the probability of 1 … Here's a quick example.....6 numbers on a dice.....the probability of 1 coming up is 1 in 61st roll: 12nd roll: 13rd roll: 14th roll: 15th roll: 1for the 6th roll you must be thinking got to be 2,3,4,5 or 6 but any number still has a 1 in 6 chance of coming up including the 1 again.Think roulette.......red or black, if red came up 24 times in a row you'd be thinking got to be black next but its still a 1 in 2 chance, same as red again.

technically less than a 1 in 2 chance on roulette as there is a green zero