Torino out how many t-shirts Karen has, first, subtract 18 from 46.
46-18=28
Now, what I would do here is guess-and-check. Whatever number of t-shirts Karen's little sister has, Karen has 6 times more.
If Karen's little sister had 4 t-shirts, then Karen would have 24 t-shirts. 4+24=28
Karen has 24 tshirts