There are six cards in which it has two king cards. all cards are turned down and two cards are opened :
a) what is the possibility to get at least one king.
b) what is the possibility to get two kings. Choose one
A) a = 1/15 , b = 3/5  B) a = 3/5 , b = 1/15  C) a = 2/15 , b = 4/5  D) a = 6/15 , b = 3/5  E) a = 6/15 , b = 7/5
Explanation :   a)   POSSIBILITY TO GET AT LEAST ONE KING IS :   =&gt; = 2C1* 4C1/6C2 + 2C2/6C2   =&gt; = 8/15+1/15   =&gt; = 3/5   b)   P0SSIBLITY TO GET TWO KINGS IS :   =&gt; =2C2/6C2   =&gt; =1/15   Hence (B) is the correct answer.   Answer : a = 3/5 , b = 1/15
<result>B</result>
There are six cards in which it has two king cards. all cards are turned down and two cards are opened :
a) what is the possibility to get at least one king.
b) what is the possibility to get two kings.