As given by the question
There are given that the 3 shirts and 2 pairs of pants and 2 caps
Now,
If she wearing a shirt and a pair of paint, then for each pair of pants, there are 3 possible shirts she can wear. Because she has 2 pairs of paint, then she has ( 3 times 2) which means 6 possible different outfits.
Now,
If she also has to decide whether or not to wear the cap, then there is (3 times 2 times 2), which means 12 outfits.