That's a lotta decks!

You have 52 ! 52! (yes fifty two factorial) decks of standard playing cards each shuffled independently.

What is the probability that at least one of them is perfectly sorted, that is the Ace through king of spades, followed by the Ace through king of diamonds, then the Ace through king of clubs, and finally the Ace through king of hearts?


Image credit : www.casino.org to


The answer is 0.63.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

Parth Sankhe
Dec 14, 2018

First, we calculate the probability (P) that none of the decks will be sorted as required.

Probability that a deck is sorted in a specific arrangement = 1 52 ! \frac {1}{52!}

Hence, probability that all decks are not sorted according to that arrangement = ( 1 1 52 ! ) 52 ! = P (1-\frac {1}{52!})^{52!}=P

Now, since 52 ! 52! is an astronomically massive number, we can consider it to tend to \infty . Hence,

P = lim x ( 1 1 x ) x P =\displaystyle \lim _{x\rightarrow ∞} (1-\frac {1}{x})^x = 1 e 0.367 \frac {1}{e}≈ 0.367

The required probability is 1 P = 0.632 1-P=0.632

Geoff Pilling
Dec 13, 2018

For N N cards, the probability of a given distribution is 1 N ! \dfrac{1}{N!}

For N combinations the probability of having none of them correct is ( N 1 N ) N (\dfrac{N-1}{N})^N

Therefore, the probability that at least one will be sorted is 1 ( N 1 N ) N 1 - (\dfrac{N-1}{N})^N

For large N N like, for example N = 52 ! N = 52! this goes 1 1 e = 0.63 1 - \dfrac{1}{e} = 0.63

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...