The probability of having a male or female child is equal (0.5).
So having your first child means you have a 50% chance of a male. Your second child being male also will have a probability of
0.5x0.5=0.25 .
The only scenario in which a couple with five children do not have at least one son is if all five children are female.
So the pribability of having five females is 0.55=0.03125
So if every other scenario means the couple have at least one son, and the total probability of an event is 1, we can find the probability of having at least one son with
