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Two jokers are added to a 52 card deck and the entire stack of 54 cards is shuffled randomly. What is the expected number of cards that will be strictly between the two jokers?

 Mar 31, 2019
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All pairs of positions (m,n) of the jokers are equally likelyP[0]=P[|mn|=1]=53(542)=227P[1]=P[|mn|=2]=52(542)=1041431P[k]=P|mn|=k+1=54k1(542)

 

The expected value of the number of cards between jokers is52k=154k1(542)k=11431(52k=153kk2)=11431(532(52)(53)16(52)(53)(105))=523

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 Mar 31, 2019

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