Question

A family has five girls and no son, probability of son as the 6th child will be :-
A.50%
B.75%
C.Full
D.No changes

Answer 1

Hint: The probability of having one son means that you could have one or two or three or four or five sons. There are a total of five situations possible. every time a woman gets pregnant and at every time there are a total 50 -50% chances to have a boy baby or a girl baby. Therefore we will treat each time the baby has the same probability to be male or female.

Complete answer:
Father is the person who is determining the sex of a child. There are two types of gametes produced by the father – X chromosome and Y chromosome. The mother only contains X chromosome. If the X chromosome containing only gametes fuses with the X chromosome of the mother, it results in a female child. If the Y chromosome containing gametes fuses with the X chromosome of the mother, it gives a male child. Thus we can say that there are 50% chances for a female child and the same for the male child, irrespectively the sex of five previously born children. There will be a total of 32 sequences of five children.

Hence the correct answer is option(A)

Note: children’s are not the side of coins. There are genetic factors that cause some people to be more likely to have daughters or sons. So we cannot take it as a straight probability question. According to the historic side, “sex at live birth” ratio of 108 males to 100 females. We can either use the crossing puzzle or the Punnett square for solving this thing.