A team of five is to be selected from amongst five boys A, B, C, D and E and four girls P, Q, R and S. Some criteria for selecation are :
A and S have to be together.
P cannot be put with R.
D and Q cannot be together.
C and E have to be together.
R cannot be put with B.
Unless otherwise stated, these criteria are applicable to all the question below :
If two of the members have to be boys, the team will consist of :
If A is selected, S has to be selected.
If B is selected, R cannnot be selected.
If D is selected, Q cannot be selected.
So, A D S Q R and B D S R Q are wrong. C E S P Q is not possible because S has to be accompanied with A.