Tine has decided to sort her school textbooks, which have been scattered all over the room so far, on the bookshelf accordingly. While tidying up, she found 5 math textbooks, 3 physics and 4 chemistry textbooks. She wanted to arrange the found textbooks on the shelf so that the textbooks for the same subjects would stand together. What is the probability that she managed to sort the textbooks the way she wanted, if she did not pay any attention to how she sorts the textbooks when sorting?
