Flight_Cadet_SRIK's blog

By Flight_Cadet_SRIK, history, 4 months ago, In English

question link:interviewbit

Supposedly a friend of yours has 2 children and at least one of them is a boy. What is the probability that the other is also a boy?

---------------------------------------------------------------------------------------------------------------------------------------- Their explanation:Byjus

answer according to their approach is 1/3.

My approach:

le the boy child be represented as B and girl as G ,younger child as 2 and elder child as 1.

So total outcomes are:((B1,B2),(B1,G2),(G1,B2),(G1,G2)).

so the known boy can be B1 or B2.

the probability of boy being elder child and he having a brother is (B1,B2)=(1/2)*(1/2).

the the probability of boy being younger child and he having a brother is (B1,B2)=(1/2)*(1/2).

so final probability =1/4+1/4=**1/2**.

OR SIMPLY BOTH ARE INDEPENDENT EVENTS

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