and wat about if he loses a\on all the three turns?????
so shudnt we add -3(5/6)3
probablity misc exercise q11.....
in a game a man wins a rupee for a six and loses a rupee for any other number when a fair die is thrown.a man decides to throw a die thrice but to quit as soon as he gets a six.Find expected value of amount he wins or loses...............
i tried it with PDF....but my answer is not matching.......
plz help.....
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15 Answers
x be the random variable of no of sixes in 3 throws of a dice
so x=0,1,2,3..........
no need to get into pdf.
winning 1 rupee is winning on the first move
winning 0 rupee is winning on 2nd move
losing 1 rupee is winning on 3rd move
losing 3 rupees ...
hence
1.1/6 +0 -1.5/6.5/6.1/6 - 3. 5/6.5/6.5/6 (thanks akand and chinmay)
but bhaiyya..........................so the expected value of the amount he wins is 11/216????????????? hws that? isnt it odd?....a fraction of money??
yes eureka
this was a wrong ncert q
i rememember getting 13/ something as ans ( long time ago )
but ans dint match
however its solved correctly in rd sharma see if ur ans matches in that
sir yehi to pdf se bhi aa raha hai............but can it be negative??????????
ok.......thanx sir for help....
i got the same ans from pdf .......but ncert confused me[2][2][2]
But if its not given what will he do if he doesn't get a six in either of the three throws. then why should we consider it.