In such type of questions, a few essential criteria for selection of a group of items are given. The candidate has to keep these conditions in mind and make the required selection as per the directions given in each question.

From amongst five doctors A, B, C, D and E, four engineers G, H, K and L and six teachers M, N, O, P, Q and R, some teams are to be selected. Of these, A, B, G, H, O, P and Q are females and the rest are males.
The formation of teams is subject to the following conditions :
Wherever there is a male doctor, there will be no female teacher.
Wherever there is a male engineer, there will be no female doctor.
There shall not be more than two male teachers in any team.

If the team consists of two doctors, one engineer and four teachers, all the following teams are possible except :

A. A B G M N O P
B. A B H M O P Q
C. A B H M R P Q
D. A B K N R P Q
Answer: D . A B K N R P Q


The doctors are A, B, C, D and E; engineers are G, H, K and L; teachers are M, N, O, P, Q and R. Four teachers are needed. There are three male teachers. So, female teachers are also to be selected. So, male doctors i.e. C, D and E cannot be selected. Thus, the two docotors selected will be A and B.
Both the doctors selected are females. So, male engineer K or L cannot be selected and either G or H is to be chosen.
Clearly, the impossible team is A B K N R P Q, because K is not to be selected.