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You cannot remember your 5-digit bike-lock combination, but you remember that all the digits are different. What is the probability that you guess the combination correctly? (Enter your probability as a fraction.)

 Jun 14, 2021
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Assuming the  first digit isn't  0  .......

 

Number of  5  digit integers =    (99999  - 10000 + 1)  =  90000

 

P( remembering)    =    1  / 90000

 

Incorrect   .......the  answer  should  be

 

10  * 9  *  8  *  7   * 6     =   30,240       

 

P (remembering  )   =    1 /30240

 

THX to EP  for pointing out my silly  error   ( he assumes  that  the combo CAN start with 0  )

 

 

cool cool cool

 Jun 14, 2021
edited by CPhill  Jun 14, 2021

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