What is the probability that no girl will choose her own dress?

Question

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?

Answer 1

Answer
total states for chooses:
1) 1 2 3
2) 1 3 2
3) 2 1 3
4) 2 3 1
5) 3 2 1
6) 3 1 2

4 and 5 and 6 are desired, hence

answer = 3/6 = 0.50