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Position from One Side

Position from One Side problems give the rank of a person from one end (left or right) and ask for the rank from the opposite end. You must use the formula: Rank from Left = Total Persons - Rank from Right + 1, or vice versa. These fundamental problems test your understanding of the relationship between left and right positions in a linear arrangement.

10Worksheets
200+Practice Questions
BeginnerDifficulty
1-2 hoursHours to Master

What You'll Learn

Introduction & Overview Why This Matters How to Solve Pro Tips & Tricks
Shortcut Methods Common Mistakes Practice Worksheets Exam Importance

Introduction to Position from One Side

Position from One Side problems give the rank of a person from one end (left or right) and ask for the rank from the opposite end. You must use the formula: Rank from Left = Total Persons - Rank from Right + 1, or vice versa. These fundamental problems test your understanding of the relationship between left and right positions in a linear arrangement.

Prerequisites

Understanding of left and right positions Basic arithmetic operations Formula: L = T - R + 1 Total persons concept
Why This Matters: Position from One Side problems are the foundation of number ranking. You can expect 2-3 questions in SSC CGL, 2-3 in Banking PO, and 2-3 in Railways RRB exams.

How to Solve Position from One Side Problems

1

Step 1: Identify the given rank (from left or right) and the total number of persons

2

Step 2: Use the formula: Rank from Left = Total - Rank from Right + 1

3

Step 3: Use the formula: Rank from Right = Total - Rank from Left + 1

4

Step 4: Substitute the known values into the formula

5

Step 5: Calculate the unknown rank

6

Step 6: Verify that the rank is between 1 and total

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Step 7: Present the answer

Pro Strategy: Always use the formula L = T - R + 1. Memorize that left rank + right rank = total + 1. This relationship holds because the same person is counted from both ends.

Example Problem

Example: In a row of 50 students, Riya's rank from the right is 15. What is her rank from the left? Solution: Step 1: Total = 50, Rank from Right = 15 Step 2: Rank from Left = Total - Rank from Right + 1 Step 3: = 50 - 15 + 1 = 36 Answer: 36th from left

Pro Tips & Tricks

  • Left rank + Right rank = Total + 1
  • If a person is at the leftmost end, left rank = 1, right rank = total
  • If a person is at the rightmost end, right rank = 1, left rank = total
  • The sum of left and right ranks is constant for a given total
  • The middle position occurs when left rank = right rank (for odd total)

Shortcut Methods to Solve Faster

L = T - R + 1
R = T - L + 1
L + R = T + 1
If given L, R = T - L + 1

Common Mistakes to Avoid

Using L = T - R instead of L = T - R + 1
Confusing left with right in the formula
Forgetting that ranks start at 1, not 0

Exam Importance

Position from One Side is an important topic for various competitive exams. Here's how frequently it appears:

SSC CGL
2-3 questions
BANKING PO
2-3 questions
RAILWAYS RRB
2-3 questions
CAT
1-2 questions
INSURANCE
2-3 questions

Ready to Master Position from One Side?

Start with Worksheet 1 and work your way up to expert level! Each worksheet includes:

20 practice questions
Detailed solutions
Step-by-step explanations
Start Practicing Now