Question

A couple has two children. Find the probability that 

(i) both children are male, if it is known that the elder child is a male. 

(ii) both children are female, it it is known that the elder child is a female. 

(iii) both children are male, if it is known that at least one of the children is male.

Answer 1

(i) Probability that both children are male and the elder child is male.

and P(B) = 1/4 + 1/4 = 2/4 = 1/2

P(Both children are female and elder child is female)