Find the probability of the following card hands from a 52-card deck.
In poker, aces are either high or low. A bridge hand is made up of 13 cards.

In bridge, exactly 3 kings and exactly 3 queens

There are 4 kings, 4 queens and 44 cards that are neither.

So to have a successful hand, we must have 3 kings, 3 queens and 7 cards that
are neither kings nor queens.

We cam pick the 3 kings "4 choose 3" or 4C3 ways.
For each of those 4C3 ways to pick the 3 kings we can pick the 3 queens any of
"4 choose 3" ways. So far we have 4C3*4C3

Now for each of those 4C3*4C3 ways to pick the 3 kings and queens, we
must choose the other 7 cards from the 44 cards that are neither kings nor
queens.  So the number of possible successful hands is 

4C3*4C3*44C7

The denominator is the number of ways to pick any 13 cards from the
52, so that's 52C13

So the desired probability is

4C3*4C3*44C7
------------
   52C13

The answer is 9.655370011×10-4 or about

.0009655370011

Edwin