Re: Daily question

Posted by Khushboo on Feb 18, 2009; 4:56pm
URL: http://discussion-forum.276.s1.nabble.com/Daily-question-tp2328964p2348066.html

1- the conditional prob is p / [ p + (1-p)(1/m) ] = mp / [mp+1-p].

2- Let E be the expected length of time that miner reaches safety.
    then, E = (1/3) (2) + (1/3) (3+E) + (1/3) (5+E)
            E = 2/3 + 1 + 1/3E + 5/3 + 1/3E
            1/3E = 2/3 + 1 + 5/3
            1/3E = 10/3
            E = 10.

3- P[both r boys] / P[atleast one of them is a boy] = 1/3
   
    Prob that both r boys gvn dat atleast one or dem is a girl = 0