A bag contains 6 white and 4 black balls. 2 balls are drawn at random.
Find the probability that they are of same color.  Choose the correct answer:
A) 7/15
B) 8/15
C) 6/15
D) 3/5
E) 8/5
let S be the sample space   Then n(S)=no of ways of drawing 2 balls out of   (6+4)= 
<gadget id="calculator">  (6+4)</gadget>
<output>10</output>
10C2=(10*9)/(2*1)= 
<gadget id="calculator">(10*9)/(2*1)</gadget>
<output>45</output>
45   Let E=event of getting both balls of same color   Then n(E)=no of ways(2 balls out of six) or(2 balls out of 4)   =(6C2+4C2)=(6*5)/(2*1)+(4*3)/(2*1)=15+6= 
<gadget id="calculator">15+6</gadget>
<output>21</output>
21   P(E)=n(E)/n(S)=21/45=7/15   answer option 7/15)7/15
<result>A</result>
A bag contains 6 white and 4 black balls. 2 balls are drawn at random.
Find the probability that they are of same color.