How do I convert a rank from one side to the other?

Rank from the other side = Total − known rank + 1. If total is 30 and a person is 12th from the left, their rank from the right is 30 − 12 + 1 = 19th.

Why do some ranking answers give two possible totals?

When the question says 'at least' or the positions of two people are given without confirming they are different people or that they do not overlap, the row could have a minimum and maximum size. Read carefully: 'exactly' fixes the count; 'at least' gives a minimum.

How common is ranking in TNPSC and bank exams?

Ranking appears as 1–3 questions in TNPSC Mental Ability and frequently in bank/SSC reasoning. They are fast, formula-based marks once you avoid the double-counting error.

Ranking and Order — Position Problems & Shortcuts | TNPSC, SSC, Bank

Quick Concept Summary

Ranking-and-order questions describe a person's position in a line "from the left" and "from the right," and ask for the total, the other-side rank, or how many people sit between two persons. Nearly every question reduces to one rule — total = left rank + right rank − 1 — plus a small, careful diagram when two people are involved.

Key Formulas

Need	Formula
Total people	left rank + right rank − 1
Rank from other side	total − known rank + 1
People between two persons	draw positions, count the gap

The single most important detail is the −1: a person is counted in both their left rank and right rank, so subtract one to avoid double-counting.

Question Types

Type 1 — Find the Total

Given a person's rank from both ends → total = left + right − 1.

Type 2 — Convert Rank Side

Given total and one rank → other-side rank = total − rank + 1.

Type 3 — Two People / Between

Mark both people's positions on a line and count the gap directly.

Type 4 — "At least" vs "Exactly"

"Exactly" fixes a unique total. "At least" gives a minimum total (people could be the same or positions could overlap).

Worked Examples

Example 1: In a row, Ravi is 9th from the left and 12th from the right. How many people are in the row? Total = 9 + 12 − 1 = 20.

Example 2: In a class of 40, Meena is 16th from the top. What is her rank from the bottom? Rank from bottom = 40 − 16 + 1 = 25th.

Example 3: In a row of 25, A is 10th from the left and B is 9th from the right. How many people sit between A and B? B's position from left = 25 − 9 + 1 = 17. A is at 10. Between = 17 − 10 − 1 = 6.

Example 4: In a queue, a person is 7th from the front and 11th from the back. Minimum people in the queue? 7 + 11 − 1 = 17.

Common Mistakes

Forgetting the −1 and getting a total that is one too high.
Mixing "rank from left" with "people to the left" (the person at rank 5 has 4 people to their left).
Counting the two endpoints when asked for people strictly between.

Exam Tips

When two people are involved, draw a quick line — it is faster and error-free.
"Exactly" → one answer; "at least" → minimum possible total.
Convert all ranks to a single side (e.g., from left) before counting gaps.

Frequently Asked Questions

Total = (rank from left) + (rank from right) − 1. The −1 prevents counting the person twice, since they are counted in both ranks. Example: if a person is 7th from left and 8th from right, total = 7 + 8 − 1 = 14.