How many floor gaps are between the floors of B and Z,

Solution

A does not live on the odd numbered floor and doesn’t live just below of the top floor. We get three possibilities here i.e. Case 1, Case 2 and Case 3. There are two floors gap between A and N, who lives above of the floor in which A lives. There are three persons live between N and M, who lives just above the floor of Y. From the given statements, Q lives below of the floor of Y but not just below. Here Case 2 is ruled out. Both B and Q do not live on ground floor. Z lives just above of the floor of Q. B lives just below of the floor of J. Here, one more case is added i.e. Case 1a. From the given statements, the number of floors gap between J and M is same as between C and Y. Now Case 1 and Case 1a are eliminated here. So, the final arrangement is such as-