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 girls, Shilpa is eighth from the left and Reena is seventeenth from the right. If they interchange their positions, Shilpa becomes fourteenth from the left. How many girls are there in the row ?
Since Shilpa and Reena interchange position, so Shilpa's new position is the same as Reena's earlier position.
This position is 14th from the left (Shilpa's new position) and 17th from the right (Reena's earlier position).
.'. Number of girls in the row = (13 + 1 + 16) = 30.