Question 1125664
I am making the very reasonable assumption that those 7 children were born at different times
(with no two of them born at exactly the same time).
Each child could be a boy, or not a boy,
giving 2 possibilities per child,
and {{{2*2*2*2*2*2*2=2^7=128}}} different ways to make up a family.
Only {{{1}}} of those {{{128}}} different ways did not have at list 1 boy.
In the other {{{128-1=highlight(127)}}} ways, there was at least one boy.
Maybe there was just 1 boy, being the first child, or the second one, or...
Maybe there were 2 boys, or 3. or...., and they were born in some order or other.
The possible ways to have one or more boys are {{{127}}} ,
and there is only {{{1}}} way to not have at least 1 boy.