Order and Ranking

Definition: Order and ranking questions describe people or objects arranged in a line and ask for someone's position or the total number in the line, given ranks counted from either end.

The Two Situations

1. Positions given from both ends → you can find the total.
2. Total and one rank given → you can find the rank from the other end.

The single most common error is double-counting the person whose rank is being measured. The formula below builds in the "+1" that corrects for this.

Real-world example: Knowing you are 7th from the front and 5th from the back of a queue tells you exactly how many people are waiting — a daily-life version of this puzzle.

Core Formula

For a single line, if a person is L-th from the left and R-th from the right:
Total = L + R - 1

Rearranged Forms

• Rank from the other end =Total - given rank + 1.
• Number of people between two positions = | position₁ - position₂ | - 1.

Watch Out

• "Above/ahead of" or "below/behind" counts exclude the person themselves.
• If some people are added or shift, redraw the line rather than reusing the old total.

Example 1. In a class, Rahul is 12th from the top and 18th from the bottom. How many students are there?
Total=12+18-1=29

Example 2. In a row of 40 children, Meena is 16th from the left. What is her position from the right?
40-16+1=25th from the right

Example 3. In a queue, A is 7th from the front and B is 9th from the front. How many people stand between them?
|9-7|-1=1 person

Quick-revision notes for Order and Ranking — the must-know points for SSC CGL Tier-I/II.

• Order/ranking finds a person's position in a row or the total number of people from partial rank information.
• Key formula: Total = (rank from left) + (rank from right) − 1.
• "Above/below" and "left/right" are relative — always fix one reference direction before counting.
• When positions from both ends are given for the same person, use the total formula directly.
• For "between" questions: people between two persons = |difference of positions| − 1.
• After interchanging seats, recompute positions carefully; the total number stays the same.

Cover the answer, recall, then check. 6 cards on the must-know Order and Ranking facts for SSC CGL.

Q1. A is 7th from left and 8th from right in a row. How many people are in the row?
A1. 14 — Total = 7 + 8 − 1 = 14.

Q2. State the core order-and-ranking formula.
A2. Total = (position from left) + (position from right) − 1.

Q3. If Ram is 5th and Shyam is 9th in the same line, how many sit between them?
A3. 3 — people between = |9 − 5| − 1 = 3.

Q4. A ranks 10th from the top in a class of 40. What is his rank from the bottom?
A4. 31st — 40 − 10 + 1 = 31.

Q5. Why subtract 1 in the total formula?
A5. Because the person is counted once from each end, so one count is duplicated and must be removed.

Q6. Two friends swap places; how does the total number in the row change?
A6. It does not change — swapping only alters individual positions, not the total count.