Answer :

AL2006
There are so many words in this problem that it sounds complicated,
and it's hard to see how simple it really is.

It tells you . . .
She has  'x'  male cousins.
She has  '2x'  female cousins.

So, how many cousins does she have altogether ?  (x + 2x) = 3x

Now it tells you . . .
She has less than 23 cousins altogether.

Fine.  So  3x  is less than  23 .

How do you write that in algebra ?

         3x < 23

Isn't it amazing how they can take something so simple
and make it seem so complicated ? ! ?