MHB Guessing a three digit pin code from an 8 key keypad

  • Thread starter Thread starter jridgeman99
  • Start date Start date
  • Tags Tags
    Code Pin
AI Thread Summary
The discussion centers on calculating the probability of correctly guessing a three-digit PIN code from an 8-key keypad, allowing for repetition of digits. Participants clarify that this scenario involves permutations since the order of digits matters, making 123 different from 321. The fundamental counting principle is applied to determine the total number of possible PIN combinations. Given the parameters, there are 512 possible PIN codes (8^3). The probability of a correct guess on the first try is therefore 1 in 512.
jridgeman99
Messages
5
Reaction score
0
Hello, the problem is as follows. I'm not sure if it is a permutation or combination problem. It says if a thief steals and ATM card and must randomly guess the correct three digit pin code from an 8 key keypad. Repetition of digits is allowed. What is the probability of a correct guess on the first try?
 
Mathematics news on Phys.org
jridgeman99 said:
Hello, the problem is as follows. I'm not sure if it is a permutation or combination problem. It says if a thief steals and ATM card and must randomly guess the correct three digit pin code from an 8 key keypad. Repetition of digits is allowed. What is the probability of a correct guess on the first try?

How many PIN codes are possible...can you apply the fundamental counting principle to answer this question?
 
I'll just add on to Mark's comment that PINs are order-sensitive. 123 is not the same as 321.
 

Thread 'What Exactly is Dirac’s Delta Function? - Insight'

Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
View full post »

Thread 'Fermat's Last Theorem'

Fermat's Last Theorem has long been one of the most famous mathematical problems, and is now one of the most famous theorems. It simply states that the equation $$ a^n+b^n=c^n $$ has no solutions with positive integers if ##n>2.## It was named after Pierre de Fermat (1607-1665). The problem itself stems from the book Arithmetica by Diophantus of Alexandria. It gained popularity because Fermat noted in his copy "Cubum autem in duos cubos, aut quadratoquadratum in duos quadratoquadratos, et...
View full post »
Thread 'Imaginary Pythagorus'

Thread 'Imaginary Pythagorus'

I posted this in the Lame Math thread, but it's got me thinking. Is there any validity to this? Or is it really just a mathematical trick? Naively, I see that i2 + plus 12 does equal zero2. But does this have a meaning? I know one can treat the imaginary number line as just another axis like the reals, but does that mean this does represent a triangle in the complex plane with a hypotenuse of length zero? Ibix offered a rendering of the diagram using what I assume is matrix* notation...
View full post »

Similar threads

MHB Possible combinations for six digit license plates, numbers 0-9 and letters a-z.
Replies
1
Views
6K
B How are permutations and probability related?
Replies
1
Views
2K
Problem Involving Combinatorics and Probability
Replies
5
Views
13K
Program to list specific permutations of 5 digits
Replies
4
Views
3K
What is the probability of guessing 3 digits out of an 8-digit number?
Replies
5
Views
3K
How many ways can a security code be formed with restrictions?
Replies
8
Views
2K
Problem involving 3 digit numbers
Replies
2
Views
2K
Possible Combinations | ATM Pin
Replies
5
Views
19K
How Many 5-Digit Numbers from 4, 5, 6, 8, 9 are Divisible by 8?
Replies
4
Views
2K
MHB How to exclude combinations for defined sequences?
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top