Question

Statement One: All girls are students.
Statement Two: All doctors are students.
Conclusions:
I. All girls are students.
II. Some students are girls.
III. Some students are doctors.
IV. All doctors are girls.

• A. Only I follows.
• B. Only I and II follows.
• C. Only II and IV follow.
• D. Only I and II and III follows.

Hint:

Both girls and doctors sit inside the students group. Ask what each premise gives when read backwards, and ask whether girls and doctors are linked to each other at all.

Answer 1

The Correct Option is D

Step 1: Understanding the Question.
Two premises are given. Both are universal affirmative statements of the form "All A are B". We have to check each of the four conclusions and keep only those that must be true whenever both premises are true.

Step 2: Key Rule or Approach.
Two rules settle this question.
First, a conclusion that simply repeats a given premise word for word is treated as following, because it is already true by the data.
Second, "All A are B" can be converted to "Some B are A". This is a standard valid conversion: if every girl sits inside the circle of students, then at least a part of the student circle is made of girls.
A universal statement can never be converted back into another universal, so "All A are B" does not give "All B are A".

Step 3: Detailed Explanation.
Conclusion I says "All girls are students". This is Statement One repeated exactly, so it follows.
Conclusion II says "Some students are girls". Convert "All girls are students" and you get exactly this, so it follows.
Conclusion III says "Some students are doctors". Convert "All doctors are students" and you get exactly this, so it follows.
Conclusion IV says "All doctors are girls". The two premises only tell us that girls and doctors both sit inside the students circle. They may overlap fully, partly, or not at all. Draw the girls circle and the doctors circle as two separate circles inside students and the premises stay true while IV becomes false. So IV does not follow.
The valid set is I, II and III.

Step 4: Checking the Wrong Options.
Option (A) keeps only I and drops II and III, both of which are valid conversions, so it is incomplete.
Option (B) keeps I and II but drops III, which follows from Statement Two in the same way II follows from Statement One.
Option (C) includes IV, which we have shown can be false, so it is wrong on that count alone.

Step 5: Final Answer.
Conclusions I, II and III follow, so the correct choice is (D).