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Study MaterialReasoningRanking Order
ReasoningStudy Material

Ranking & Order

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Ranking & Order

Subject: Reasoning | Frequency: 1-2 questions per APPSC paper | Time: 30-45 sec/question


Introduction

Ranking questions involve positions in a row, class, or queue. You must find total count, convert rank from one end to another, or count people between two positions. The formula T = L + R - 1 (Total = rank from Left + rank from Right - 1) is the single most important formula and solves 80%+ of ranking questions.


Core Method

  1. Identify what's given — rank from top/left, rank from bottom/right, total
  2. Identify what's asked — convert, count between, find total
  3. Apply the appropriate formula
  4. Check for overlap — when two positions are given, verify they could be the same or different person
  5. Verify — answer must be a positive integer

Key Formulas

FormulaUsage
Total = Left + Right - 1Find total from two positions of same person
Position from other end = Total - Position + 1Convert rank from one end to other
People between (non-overlap) = Total - Pos1 - Pos2When positions from opposite ends
People between (overlap) = Pos1 + Pos2 - Total - 2When positions overlap

Worked Examples — Easy

Q1: In a class of 46 students, Anita ranks 12th from top. What is her rank from bottom?

  • Rank from bottom = Total - Rank from top + 1
  • = 46 - 12 + 1 = 35th

Q2: Rakesh ranks 7th from top and 28th from bottom. How many students in class?

  • Total = 7 + 28 - 1 = 34 students

Q3: In a row of 40 children, Manu is 13th from the left. Position from right?

  • Position from right = 40 - 13 + 1 = 28th

Worked Examples — Medium

Q4: Ravi is 7 ranks ahead of Sumit in a class of 39. Sumit is 17th from last. Ravi's rank from start?

  • Sumit's rank from start = 39 - 17 + 1 = 23rd
  • "7 ranks ahead" = lower rank number = 23 - 7 = 16th from start

Q5: Shilpa is 8th from left, Reena is 17th from right. After interchange, Shilpa becomes 14th from left. Total girls?

  • After interchange: Shilpa now at Reena's original position
  • Shilpa's new position from left = 14
  • Reena's original position from right = 17
  • Total = 14 + 17 - 1 = 30 girls

Q6: Mohan is 15th from left. Sohan is 20th from right. 8 people between them. Total? (non-overlapping)

  • Total = 15 + 20 + 8 = 43
  • (Alternative if overlapping: 15 + 20 - 8 - 2 = 25 — check which answer appears in options)

Worked Examples — Hard

Q7: Manish ranks 16th from top and 29th from bottom among passed students. 6 boys didn't participate; 5 failed. Total boys in class?

  • Passed = 16 + 29 - 1 = 44
  • Total = Passed + Failed + Non-participants = 44 + 5 + 6 = 55

Q8: Five friends: Mohan older than Prabir. Suresh younger than Prabir. Mihir older than Suresh but younger than Prabir. Ram is youngest.

  • Order (oldest to youngest): Mohan > Prabir > Mihir > Suresh > Ram
  • Middle position: Mihir

Q9: In a row of 50 people, A is 20th from left, B is 30th from right. People between A and B?

  • B from left = 50 - 30 + 1 = 21
  • A at 20, B at 21 → adjacent
  • People between = 0

Shortcuts & Tricks

ShortcutWhen to Use
T = L + R - 1Most-used formula; memorize it cold
Position conversionOther end = Total - This end + 1
Interchange trickNew position from left = other person's old position from left
"Ahead" = lower number"5 ranks ahead" means subtract 5 from rank
Between (non-overlap)Between = Total - sum of both positions
Draw number lineFor complex problems, mark positions on a line

Common Mistakes

  1. Forgetting the -1 — Total = Top + Bottom - 1 (not just Top + Bottom)
  2. "Ahead" direction — "7 ranks ahead" from position 23 = position 16 (subtract, not add)
  3. Overlap vs non-overlap — must check if two people's positions overlap or not
  4. Mixing left-right with top-bottom — same formulas apply, but keep terminology consistent
  5. Not checking integer results — if the answer isn't a whole number, recheck your setup

Exam Strategy

  • Memorize T = L + R - 1 and position conversion — these two solve 80%+ of questions
  • APPSC keeps difficulty at easy-to-medium
  • Time: 30-45 seconds per question
  • For "between" questions, always check if two people could be the same person (overlap)
  • Negative marking: -0.333 — formula-based questions give very high confidence

Practice Questions

  1. Class of 30, Rani is 10th from top. Rank from bottom? → 30 - 10 + 1 = 21st
  2. 5th from left and 18th from right. Total? → 5 + 18 - 1 = 22
  3. Class of 45, 12th from top and 26th from bottom. Same person? → 12 + 26 - 1 = 37 (not 45, so different person)
  4. A is 15th from left in row of 50. B is 20th from right. Between them? → B from left = 31. Between = 31 - 15 - 1 = 15
  5. Rank from top = 3x rank from bottom, total = 61. Rank from bottom? → 3x + x - 1 = 61, 4x = 62, x = 15.5 (not integer → check question)

Key Terms / Formulas

TermMeaning
T = L + R - 1Total = position from left + position from right - 1
Position conversionOther end = Total - This end + 1
"Ahead" / "Before"Lower rank number (closer to top/front)
"Behind" / "After"Higher rank number (closer to bottom/back)
OverlapWhen sum of two positions from opposite ends < Total + 1
Non-overlapWhen sum of two positions from opposite ends > Total + 1

Ready to test yourself?

Practice MCQs for Ranking Order