In Ranking Sequence questions, ranks of a person both from the top and bottom are mentioned and total number of persons is asked. However, sometimes this question is put in the form of a puzzle of interchanging seats by two persons.
In a row of trees, one tree is fifth from either end of the row. How many trees are there in the row ?
Justification: Clearly, number of trees in the row = ( 4 + 1 + 4 ) = 9.