1 A couple wants to have two children. What is the probability that
(a) the first or the second is a boy (= at least one girl),
(b) both children have same gender,
(c) what is the probability for having two boys knowing that there is (=under condition of having) at least one boy?
(a) the first or the second is a boy (= at least one girl),
(b) both children have same gender,
(c) what is the probability for having two boys knowing that there is (=under condition of having) at least one boy?