A bag contains 4 black, 5 yellow and 6 green balls. Three balls are drawn at random from the bag. What is the probability that all of them are yellow?  Pick:
A) 2/81
B) 2/91
C) 1/81
D) 1/91
E) 1/51
Total number of balls = 4 + 5 + 6= 
<gadget id="calculator">4 + 5 + 6</gadget>
<output>15</output>
15   n(S)= tot no of ways of drawing 3 balls out of 15 =15c3   let E = event of drawing 3 balls   n(E) = no of ways of drawing 3 balls   = no of ways of drawing 3 balls from the total 5 = 5c3   =&gt;(5*4/2*1)/(15*14*13/3*2*1)=2/91   ANSWER 2/91
<result>B</result>
A bag contains 4 black, 5 yellow and 6 green balls. Three balls are drawn at random from the bag. What is the probability that all of them are yellow?