What Are the Odds of Finding a Car License With Triple 9

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Discussion Overview

The discussion revolves around the probability of encountering car license plates with three consecutive 9's. Participants explore various formats of license plates from different regions, share observational data, and consider the implications of randomness in license plate assignments.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants suggest that the odds of finding a plate with three consecutive 9's depend on the total number of cars and the specific license plate format in different regions.
  • One participant mentions that in the UK, older plates had three numbers, making the odds roughly 1/999, but notes that current formats have changed.
  • Another participant proposes using basic probability formulas based on observational data from different countries.
  • Some participants express uncertainty about the distribution of license numbers and the impact of government regulations on certain numbers, like 666 and 999.
  • Observational data shared indicates that out of 50 cars, none had a triple 9, but some had double 9's and other repeating numbers.
  • One participant calculates the probability of having a double 9 or triple 9 based on random 4-digit numbers, suggesting that the probability of a triple 9 is about 0.2%.
  • There is mention of different license plate formats, leading to questions about what specific format is being referred to in the original inquiry.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the exact odds or methods for determining the probability of finding a license plate with three consecutive 9's. Multiple competing views and uncertainties remain regarding the distribution of license numbers and the impact of regional formats.

Contextual Notes

Limitations include a lack of specific data on license plate distributions in various regions, potential biases in observational data, and the influence of government regulations on certain number combinations.

Navin
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One of my classmates asked me what would be the odds of finding a car plate no with three comsequetive 9's on it.

This ISN'T A HOMEWORK QUESTION

Just a random thought.

So...if anyone is from different places of the Earth with different car plate formats ,could you'll inform ?
 
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Navin said:
One of my classmates asked me what would be the odds of finding a car plate no with three comsequetive 9's on it.

This ISN'T A HOMEWORK QUESTION

Just a random thought.

So...if anyone is from different places of the Earth with different car plate formats ,could you'll inform ?

In the UK there are only two digits in the plate nowadays. But, there may be a few personalised plates or older plates.

The best answer is that you have to count the total number of cars on the road and count how many have 999 in the plate.
 
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PeroK said:
In the UK there are only two digits in the plate nowadays. But, there may be a few personalised plates or older plates.

The best answer is that you have to count the total number of cars on the road and count how many have 999 in the plate.
Great...

So ill take a total of 50 cars i see in one day...and then use basic probability formula

But i don't think my state will encompass the whole globe.

So I am going to have to ask a bunch of people from diff countries to do a similar observation and tell...right ?

Is there any other fancy shwancy way though ?
 
Navin said:
Great...

Is there any other method...i don't know some complex differntiation intervration or some cryptic formula or something ? I mean although i can get a perfect method by this answer...3 million cars are there in my state alone...let alone the world !

In the old days British cars had three (*) numbers and they were generally random from 1 to 999. So, the odds were, give or take, 1/999.

(*) I think they were up to three numbers, so you could have "6" or "31" or "522" etc.

But, then, the government started to hold back special numbers and sell these. And, then, they decided to have just two numbers.

So, now, without looking at the government's licensing database, I have no idea how many 999's there are on the British roads.

The only way you can use mathematical probability theory is if you know how license numbers are distributed.
 
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PeroK said:
In the old days British cars had three (*) numbers and they were generally random from 1 to 999. So, the odds were, give or take, 1/999.

(*) I think they were up to three numbers, so you could have "6" or "31" or "522" etc.

But, then, the government started to hold back special numbers and sell these. And, then, they decided to have just two numbers.

So, now, without looking at the government's licensing database, I have no idea how many 999's there are on the British roads.

The only way you can use mathematical probability theory is if you know how license numbers are distributed.
Darn it ! And such info we lack...

Ps : 3 consequetive numbers are extremely common in India ! We have a four no. Number plate
 
Probably 1/998 as maybe they were superstitious and took 666 out of the distribution
 
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BWV said:
Probably 1/998 as maybe they were superstitious and took 666 out of the distribution
Whoa ! Really ! Thats rather cool actually
 
Okay guys...today i took down observations.

Out of 50 cars i saw on the road...0 had a triple 9 on the no. Plate.
I saw 2 with a double 9 and 12 had repeating numbers consequetvely but none had a triple 9.
 
Ill try again tom.
 
  • #10
I wouldn't be surprised if some states prohibited 666 and 999
 
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  • #11
phinds said:
I wouldn't be surprised if some states prohibited 666 and 999
In India we don't consider it such a big deal,so I am pretty sure there are cars out there ! Finding them is the problem !
 
  • #12
Navin said:
One of my classmates asked me what would be the odds of finding a car plate no with three comsequetive 9's on it.

This ISN'T A HOMEWORK QUESTION

Just a random thought.

So...if anyone is from different places of the Earth with different car plate formats ,could you'll inform ?
But I have seen license plates with wildly different formats: Letter Number Letter Letter... etc. What format is your classmate referring to.
 
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  • #13
Navin said:
Okay guys...today i took down observations.

Out of 50 cars i saw on the road...0 had a triple 9 on the no. Plate.
I saw 2 with a double 9 and 12 had repeating numbers consequetvely but none had a triple 9.

If the licences are random 4-digit numbers (including 0), then the probability of having a double 9 somewhere is about 2.7%. That's about one in every 37 cars.

But, the probability of having a triple 9 is only about 0.2%. That's only one car in every 500.

The probability of having any double is about 24%; about one car in every 4.

Your data fits these calculations.
 
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  • #14
PeroK said:
If the licences are random 4-digit numbers (including 0), then the probability of having a double 9 somewhere is about 2.7%. That's about one in every 37 cars.

But, the probability of having a triple 9 is only about 0.2%. That's only one car in every 500.

The probability of having any double is about 24%; about one car in every 4.

Your data fits these calculations.
WWGD said:
But I have seen license plates with wildly different formats: Letter Number Letter Letter... etc. What format is your classmate referring to.

I don't think he knew that himself to be honest !
But I am sure he will be satisfied by PeroK 's answer because that's the format we use in India .Anyway Thank you all for contributing in this thread and helping me ! It was extremely kind of you'll.

Have a great day ahead.

If you'll have anything more to say please feel free to do so.
 
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