A teacher will pick a group of 4 students from a group of 9 students that includes Bart Lisa and john. If one of all the possible four-student groups is picked at random, what is the probability of picking a group that includes john Bart and Lisa?	Pick one.
A) 1/7  B) 3/14  C) 1/4  D) 1/21  E) 3/7
Probability = Favorable Outcomes / Total Outcomes   Total Outcomes= Total No. of ways of Picking Group of 4 out of 9 = 9C4 = 9! / (5! * 4!) = 126   Favorable Outcomes= Total No. of ways of Picking Group of 4 out of 9 such that J, B and L are always in the group (i.e. we only have to pick remaining one out of remaining 6 as J, B and L must be there is group) = 6C1 = 6   Hence,Probability=6/126=1/21   Answer: Option 1/21
<result>D</result>
A teacher will pick a group of 4 students from a group of 9 students that includes Bart Lisa and john. If one of all the possible four-student groups is picked at random, what is the probability of picking a group that includes john Bart and Lisa?