1. 

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?

A. Engineer, professor, doctor, IAS officer, MLA
B. Professor, engineer, doctor, IAS officer, MLA
C. IAS officer, engineer, doctor, professor, MLA
D. Professor, engineer, doctor, MLA, IAS officer

Answer: Option D

Explanation:

The order is as follows

4th ---> IAS officer

3rd ---> MLA

2nd ---> Doctor

1st --> Engineer/Professor

Ground ---> Professor/Engineer

But from the given options, only option (d) follows, i.e. from ground floor to top floor, order is professor, engineer, doctor, MLA, IAS officer.