These events are independent; so the probability of a girl is 0.5.
In a family with four children, the probability of having four boys is 1 in 16.
25
1/8
1/4
50/50
50/50
Since the probability of having a son is about 1/2, the probability of the first 4 children being boys is about (1/2)4.
In a family with four children, the probability of having four boys is 1 in 16.
25
If we consider there is a 50% chance for having a boy and 50% for having a girl*, there is : - 12,5% chance of having no boys; - 37,5% chance of having 1 boy; - 37,5% chance of having 2 boys; - 12,5% chance of having 3 boys. Therefore, there is 50% chance of having at least two boys. *The odds are more like 51% for having a boy and 49% for having a girl, but it doesn't really matters.
1/8
3/8
Assuming that having boys and girls are equally likely, then the probability is 1/8. * * * * * You also need to assume that the children's genders are independent. They are NOT and depend on the parents' ages and genes.
1/4
Assuming the probability of having a boy is 1/2, and that the probabilities are independent: Probability of 1 girl and 12 boys = (1/2)13 * 13 = 0.001587..., which is around 1/630
50/50
1/32