Answer:
33.3% probability that both children are girls, if we know that the family has at least one daughter named Ann.
Explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
The family has two children.
The sample space, that is, the genders of the children may be divided in the following way, in which b means boy and g means girl.
b - b
b - g
g - b
g - g
We know that they have at least one girl. So the sample space is:
b - g
g - b
g - g
What is the probability that both children are girls, if we know that the family has at least one daughter named Ann?
Desired outcomes:
Both children being girls, so
g - g
1 desired outcome
Total outcomes
b - g
g - b
g - g
3 total outcomes
Probability
1/3 = 0.333
33.3% probability that both children are girls, if we know that the family has at least one daughter named Ann.