In a box there are 22 cubes, 12 red and 10 blue.

7 cubes are chosen at random.

Find the probability for the following events:

a. Among the seven cubes there are 4 blue cubes and 3 red cubes

There are others, but I've tried to do them, and for a I get something like..

0.00780 or something like that.

Which I think might be wrong..

So if anyone could just show me what to do, I think I can do the rest myself, thanks