Q.
Let S={w1β,w2β,β¦.} be the sample space associated to a random experiment. Let P(wnβ)=2P(wnβ1β)β,nβ₯2.
Let A={2k+3β;k,ββN} and B={wnβ;nβA}. Then P(B) is equal to
Let P(w1β)=Ξ» then P(w2β)=2Ξ»ββ¦P(wnβ)=2nβ1Ξ»β
As k=1βββP(wkβ)=1β1β21βΞ»β=1βΞ»=21β
So, P(wnβ)=2n1β A={2k+3β;k,ββN}={5,7,8,9,10β¦..} B={wnβ:nβA} B={w5β,w7β,w8β,w9β,w10β,w11β,β¦.} A=Nβ{1,2,3,4,6} β΄P(B)=1β[P(w1β)+P(w2β)+P(w3β)+P(w4β)+P(w6β)] =1β[21β+41β+81β+161β+641β] =1β6432+16+8+4+1β=643β