In five flats, one above the other, live five professionals. The professor has to go up to meet his IAS officer friend. The doctor is equally friendly to all, and has to go up as frequently as go down. The engineer has to go up to meet his MLA friend above whose flat lives the professor’s friend. From the ground floor to the top floor, in what order, do the five professionals live?

Correct Option

The problem requires determining the precise living order of five professionals in a building with five flats, one above the other. Let's assign flat numbers from 1 (ground floor) to 5 (top floor).

• The statement "The doctor is equally friendly to all, and has to go up as frequently as go down" indicates that the Doctor resides in the middle flat. With five flats, the Doctor occupies flat 3.
• The statement "The professor has to go up to meet his IAS officer friend" implies that the Professor lives below the IAS officer (Professor < IAS officer).
• The statement "The engineer has to go up to meet his MLA friend above whose flat lives the professor’s friend" provides two critical pieces of information:
  • The Engineer lives below the MLA (Engineer < MLA).
  • The Professor's friend is the IAS officer. Therefore, the IAS officer lives above the MLA (MLA < IAS officer).

Combining these deductions, we establish the following relationships:

• Doctor is in flat 3.
• Engineer < MLA < IAS officer.
• Professor < IAS officer.

Given the Doctor is in flat 3, and the sequence Engineer < MLA < IAS officer must be maintained in ascending order, these three professionals must occupy flats 2, 4, and 5 respectively. This arrangement places the Engineer below the Doctor, and the MLA and IAS officer above the Doctor, while preserving their relative order. The remaining professional is the Professor.

Placing the Professor in the remaining flat 1 satisfies the condition Professor < IAS officer (1 < 5).

Therefore, the final order from ground floor to top floor is: Professor (1), Engineer (2), Doctor (3), MLA (4), IAS officer (5).

Incorrect Options

• Option 1 (Engineer, Professor, Doctor, IAS officer, MLA): In this arrangement, the MLA is in flat 5 and the IAS officer is in flat 4. This contradicts the condition that the IAS officer lives above the MLA (MLA < IAS officer).

• Option 2 (Professor, Engineer, Doctor, IAS officer, MLA): In this arrangement, the MLA is in flat 5 and the IAS officer is in flat 4. This contradicts the condition that the IAS officer lives above the MLA (MLA < IAS officer).

• Option 3 (IAS officer, Engineer, Doctor, Professor, MLA): In this arrangement, the Professor is in flat 4 and the IAS officer is in flat 1. This contradicts the condition that the Professor lives below the IAS officer (Professor < IAS officer).