What is the position of Y with respect to Z?

We have, Y is three persons senior to Z. Only one person is designated between Z and W. From the above condition, there are two possibilities Again we have, More than two persons are designated between W and X, who is junior to Y. As many persons designated between Y and X is same as between U and Z. V is two persons junior to T. As many persons senior to T is same as junior to W. From the above conditions, case S and case Ia get eliminated. Hence case II shows the final arrangement. Hence case II shows the final arrangement.