but I am not sure. It seems like the ball and urn type problem where Bayes Theorem can be easily applied but it is not quite the same. Can anybody help me out?

A box contains 25 computer diskettes, 5 of which are double density and the remainder are high density. A second box contains 15 diskettes, 10 double density and 5 high density. A box is selected at random and then two diskettes are chosen randomly from the selected box. What is the probability that both diskettes are high density?