
The diagram overlaps three rectangles, College Students, Singers and Dancers, and each small box represents a specific combination of the three. The question asks for college students who are neither singers nor dancers, so every choice can be checked against the picture.
Region P is the only one that is genuinely inside College Students while being outside both other groups, so it is the correct region. Note that some printed answer keys for this question mark option (d), Q, but that region lies outside the College Students boundary in the diagram itself, the same way V is outside it and is correctly ruled out as the answer to the dancers-and-singers question. Using the diagram consistently, the same way it correctly gives R, S and T for the earlier three questions, points to P here.
Let's summarize:
So college students who are neither dancers nor singers are represented by P.
In the following figure, the smaller triangle represents teachers; the big triangle represents politicians; circle represents graduates and rectangle represents members of Parliament. Different regions are being represented by letters of English alphabet. On the basis of the above diagram, answer the following questions: 
Consider the Diagram. 500 Candidates appeared in an Examination comprising test in English, Hindi and Maths. The Diagram gives number of students who failed in different tests. What is the percentage of student who failed at least two subjects?
