We have  `n (S) ` = ` 52_(C_ 2) = ((52 xx 5))/((2 xx 1))` = 1326

Let    A = event of getting both black cards .

         B = event of getting both queens..

`:.`     `A nn B` = event of getting queens of black cards.

`:.`      `n (A) =  26_(C_ 2) = ((26 xx 25))/((2 xx 1))` = 325.

           `n (B) ` = `4_ (C_ 2) = ((4 xx 3))/((2 xx 1))` = 6

and   `n (A nn B) =  2_ (C_ 2)` = 1 

`:.`     P (A) = `(n(A))/(n(S)) = 325/1326,`

         P (B) = `(n(B))/(n(S)) = 6/1326`

and ` P (P nn B) = (n(A nn B))/(n(S)) = 1/1326`

`:.`    `  P ( A uu B)  = P(A) + P(B) - P(A nn B)`

=`( 325/1326 + 6/1326 -  1/1326) =  330/1326 = 55/221`