Conditional Probability q1 Revision as of 14:20, 12 December 2013 by Arjun Suresh (talk | contribs) (Created page with "A man visits a couple who have 2 children. one of the children, a boy, comes into the room. find the probability p that the other is also a boy. (a)1/3 (b)2/3 '''(c)1/2''' (d...") (diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

A man visits a couple who have 2 children. one of the children, a boy, comes into the room. find the probability p that the other is also a boy.

(a)1/3 (b)2/3 (c)1/2 (d)3/4

Solution

Since, it's given that the first one is a boy, the second event is independent of the first and the probability is 1/2. Had it been "one of the children is a boy" instead of "first one is a boy" then the probability of two children being boys would have been 1/3 (sample space BB, BG, GB).

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