Find the probability of being same

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In summary, the conversation discusses the probability of two files (A and B) of size 8192 bytes being the same, based on their bit sequences. The sample space (S) includes all possible bit sequences for file A, and the formula used to calculate the probability is n(E)/ n(S) =1/2^65536. However, the problem becomes more complex when both files are filled with 1s in the first 16384 bits. The speaker acknowledges that their approach may not be correct and asks for help in finding the probability in this scenario.
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Diganta281
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This question is somewhat related to computer but deals with a big lot of probability.I have been given two files (A and B) of size 8192 bytes and is asked to find the probability of that file B is same as file A.I know that for two files to be same, they should have same bit sequence i.e same sequence of 1s and 0s.
As the files are of 8192 bytes so they have (8192*8) i.e 65536 bits.
Now our sample space (S) includes all the probable bit sequences of file A.
Using the formulae variation^length, I got that n(S)=2 ^65536
[Since , variations are 1 and 0 i.e 2 variations and length =65536 bits]
Now , Since file B can have only one sequence of bits
\therefore n(E)=1 [let E denote the set of favourable outcomes to the event that file B is same as file A]
\therefore probability of the matching of the two files = n(E)/ n(S) =1/2^65536 = 2^-65536

Upto this it is clear to me but the real problem starts in the next part :
In the next part of problem it is given that file A as well as file B have 16384 bits filled with 1s and the rest bits filled with 0s.
Now certainly the above found probability would increase as in the above part we have considered that both file A and B can have as many 1s and 0s required to fill the complete sequence of bits.
Now I am not able to figure out what the probability of both the files being same would be!
Plz help me soon...
 
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  • #2
Diganta28 said:
This question is somewhat related to computer but deals with a big lot of probability.I have been given two files (A and B) of size 8192 bytes and is asked to find the probability of that file B is same as file A.I know that for two files to be same, they should have same bit sequence i.e same sequence of 1s and 0s.
As the files are of 8192 bytes so they have (8192*8) i.e 65536 bits.
Now our sample space (S) includes all the probable bit sequences of file A.
Using the formulae variation^length, I got that n(S)=2 ^65536
[Since , variations are 1 and 0 i.e 2 variations and length =65536 bits]
Now , Since file B can have only one sequence of bits
\therefore n(E)=1 [let E denote the set of favourable outcomes to the event that file B is same as file A]
\therefore probability of the matching of the two files = n(E)/ n(S) =1/2^65536 = 2^-65536

Upto this it is clear to me but the real problem starts in the next part :
In the next part of problem it is given that file A as well as file B have 16384 bits filled with 1s and the rest bits filled with 0s.
Now certainly the above found probability would increase as in the above part we have considered that both file A and B can have as many 1s and 0s required to fill the complete sequence of bits.
Now I am not able to figure out what the probability of both the files being same would be!
Plz help me soon...

Your approach to the problem would be fair if any combination of 8192 bytes had the same probability, and this clearly is not true ... I think your question isn't easy to answer ...

Kind regards

$\chi$ $\sigma$
 

FAQ: Find the probability of being same

What is the definition of "probability"?

Probability is a measure of the likelihood of an event occurring. It is expressed as a number between 0 and 1, with 0 representing impossibility and 1 representing certainty.

How do you calculate the probability of being same?

To calculate the probability of being same, you need to divide the number of possible outcomes where the event of interest occurs by the total number of possible outcomes. This can be represented as P(A) = Number of favorable outcomes / Total number of possible outcomes.

What factors affect the probability of being same?

The factors that can affect the probability of being same include the sample size, the randomness of the sample, and the underlying distribution of the data. Other factors such as bias and measurement errors can also impact the probability.

Can the probability of being same be greater than 1 or less than 0?

No, the probability of being same cannot be greater than 1 or less than 0. If the probability is greater than 1, it means that the event is certain to occur, which is not possible. If the probability is less than 0, it means that the event is impossible, which is also not possible.

How is probability used in real-life situations?

Probability is used in a variety of real-life situations, such as in gambling, insurance, weather forecasting, and decision-making. It helps us make informed predictions and assess risks in various scenarios.

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