How many persons are sitting in the row?

Explanation

We are given with the data-No one sits to the right of N, who is second to the right of P. X is third to the left of P. Q is second from one of the extreme ends. It means N sits at the extreme right end. Five person sit between M and X. M sits fourth to the right of S. Four persons sit between S and U. The number of persons between M and U is same as between S and T. T sits at one of the positions to the left of S. Not more than two persons sit between U and Q. Now, in case 1, will be rejected as there are more than two persons sitting between Q and U. We will continue with case 2. Thus the final arrangement is as follows-Case 2 -