Answer:
1/8.
Explanation:
Since there are only two gender you can be born in from birth (boy or girl) we have 1/2 chance that the first child will be a girl.
The second child will also have 1/2 of being a girl, and the third child too will have 1/2 chance of being a girl.
Multiple them all together, and what you get will be the answer.
(1/2) * (1/2) * (1/2) = 1/8
NOTE: THIS IS UNDER THE ASSUMPTION THAT MRS. DIAS HAS 1/2 CHANCE OF RECIEVING A GIRL.
IN A REAL LIFE SITUATION, THIS WOULD PROBABLY BE VERY RARE, SINCE WOMEN USUALLY HAVE A TENDENCY TO BIRTH EITHER MORE SONS THAN DAUGHTERS OR MORE DAUGHTERS THAN SONS.
This means that women usually have a higher probability to birth sons than daughters, or have a higher probability to birth more daughters than sons.
However, to have equal chances... that's pretty rare.
However, since this is a math question, I just assumed that there would be equal chances of getting a girl or boy since the question never said the probability of getting a girl was for Mrs. Dias.