A bag contains 4 white, 5 red and 6 blue balls. Three balls are drawn at random from the bag. The probability that all of them are red, is: Select the correct option:
A) 1/22 B) 3/22 C) 2/91 D) 5/91 E) 3/91
Let S be the sample space.   Then, n(S)= number of ways of drawing 3 balls out of 15   = 15C3   =(15 x 14 x 13)/(3 x 2 x 1)   = 455.   Let E = event of getting all the 3 red balls.   n(E) = 5C3 = 5C2 =(5 x 4)/(2 x 1)= 10.   P(3/91) =	n(3/91)/n(S)=10/455=2/91.
<result>E</result>
A bag contains 4 white, 5 red and 6 blue balls. Three balls are drawn at random from the bag. The probability that all of them are red, is: