a box contains 25 computer diskettes, 5 of which are double density and the remiander 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?

Question

a box contains 25 computer diskettes, 5 of which are double density and the remiander 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?

bobpursley · Answer

The probabality of selecting a HD is (20+5)/(25+15) * (24)/(39) There are longer and more complicated of working this out.

Josh_DB9 · Answer

can you explain?