An aptitude test contains 4 questions from verbal reasoning, 5 questions from simple mathematics and 6 questions testing knowledge of English. Three questions are selected at random from the list of questions. The probability that all of them are from simple mathematics section, is:	Choose the correct choice from the following:
A) 2/91
B) 1/22
C) 3/22
D) 2/77
E) None of these
Explanation :   Let S be the sample space.   Then, n(S) = number of ways of selecting 3 questions out of 15= 15C3= (15 x 14 x 13)/(3 x 2 x 1)= 455   Let E = event of getting all the 3 questions from simple mathematics section.   n(E) = 5C3 = 5C2 = (5 x 4)/(2 x 1) = 10   P(E) = n(E)/n(S) = 10/455 = 2/91 .   2/91nswer : 2/91
<result>A</result>
An aptitude test contains 4 questions from verbal reasoning, 5 questions from simple mathematics and 6 questions testing knowledge of English. Three questions are selected at random from the list of questions. The probability that all of them are from simple mathematics section, is: