FlyerTalk Forums - View Single Post - Booking / PNR Query : no numbers in a BA PNR
Old Dec 27, 2024 | 2:22 am
  #15  
DeathSlam
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Originally Posted by BertieBadger
I believe numeral 1 is omitted in Amadeus, so a quick bit of (very likely wrong) number crunching gives very roughly 1 in 5 of all letters, against 1 in 6000 of being all numbers. That assumes a random distribution which it may not be..
Yes, I think it looks like this...
26 letters + 8 numbers (assuming 0 and 1 omitted) = 34 possible characters to choose from for each of the six in a PNR
If random, the chances of it all being letters means you must pick one of the letters for each position, so choosing one of 26 from 34.
(26/34)*(26/34)*(26/34)*(26/34)*(26/34)*(26/34)=0.19997... So 1 in 5.
All numbers would need to choose 8/34 at each position and the same treatment gives 0.0001697... Which is 1 in 5892

But I also agree that it may not be random. It would surprise me if there wasn't someone on FT who knew.
However the numbers you found seem to be close enough to common experience that they may just simply be correct.
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