Aug 20, 2010

Number of Sons


A man has two children. He says one of them is a son. What is the probability that the other one is also a son? (Hint: Answer is not 0.5 :P)

I have read this problem many times in many different forms. But still looks fresh :P


Read the wikipedia article of a famous and related problem (Link)


  1. There are only three cases now than four because GG is eliminated.
    Cases are: GB; BG; BB
    SO the required probability is: 1/3


Fraction Brainteaser

Source: Sent to me by Gaurav Sinha Problem: Siddhant writes a Maths test and correctly answers 5 out of 6 Arithmetic questions and 20...