Ten persons in an organization including A and B were to be divided in two groups of 5 members each. The total number of groups containing both A and B is what fraction of the total number of groups which can be formed?	Choose the correct choice:
A) 1/4	B) 1/189	C) 3/14	D) 1/10	E) 28/189
The fraction is nothing but the probability..   Number to choose 5 out of 10= 10C5   Number to choose A and B and 2 from remaining 8=8C2..   prob of A and B choosen=8C2/10C5=28/189   Answer :28/189
<result>E</result>
Ten persons in an organization including A and B were to be divided in two groups of 5 members each. The total number of groups containing both A and B is what fraction of the total number of groups which can be formed?