Ranking & Time Sequence | Complete Guide with Formulas, Tricks & Examples

26 views Ch 09: Ranking and Time Sequence

🏆 Chapter 09: Ranking & Time Sequence

Master Position-Based Logic & Chronological Reasoning


📖 1. What is Ranking?

Definition

Ranking refers to arranging people, objects, or events in a specific order based on position, performance, height, weight, age, or any other criterion.


💡 Real-World Examples

Scenario Ranking Type Example
Class Performance Merit-based Ram is 5th in class of 40 students
Height Arrangement Physical attribute Tallest to shortest in a line
Race Competition Speed-based Winner, 1st runner-up, 2nd runner-up
Age Comparison Time-based Oldest to youngest sibling

🎯 Why is This Important?

Benefit Application
Logical Positioning Understanding relative positions in sequences
Comparative Analysis Comparing multiple elements simultaneously
Exam Relevance Common in aptitude tests and competitive exams
Real-Life Skills Queue management, scheduling, priority setting

📊 2. Types of Ranking Problems

📌 Type 1: Rank from Top/Bottom

Understanding position from either end of a sequence.


🔢 Basic Ranking Formula

Formula When to Use Variables
Total = Rank from Top + Rank from Bottom - 1 Finding total number T = Total, Rt = Rank from top, Rb = Rank from bottom
Rank from Top = Total - Rank from Bottom + 1 Finding rank from top When total and bottom rank given
Rank from Bottom = Total - Rank from Top + 1 Finding rank from bottom When total and top rank given

✏️ Example 1: Finding Total Students

Problem: In a class, Ram ranks 7th from the top and 28th from the bottom. How many students are in the class?

Step-by-Step Solution:

Step Information Calculation Result
Given Rank from top (Rt) 7 -
Given Rank from bottom (Rb) 28 -
Formula Total = Rt + Rb - 1 7 + 28 - 1 34 students
Why -1? Ram is counted in both ranks Avoid double counting

Visual Representation:

Top → 1, 2, 3, 4, 5, 6, [7-RAM], 8, 9, ... 27, 28 ← Bottom
      ←―――― 7 from top ――――→ RAM ←―――― 28 from bottom ――――→

Answer: 34 students


✏️ Example 2: Finding Rank from Bottom

Problem: In a row of 50 students, Sita is 12th from the top. What is her rank from the bottom?

Step-by-Step Solution:

Step Information Calculation Result
Given Total students (T) 50 -
Given Rank from top (Rt) 12 -
Formula Rb = T - Rt + 1 50 - 12 + 1 39th from bottom
Verify 12 + 39 - 1 50 ✓ Correct

Answer: 39th from bottom


📌 Type 2: Position After Rearrangement

When positions change due to new arrangements.


✏️ Example 3: Position Change

Problem: In a queue of 40 people, Mohan is 16th from the front. If every alternate person from the front is removed, what will be Mohan's new position?

Step-by-Step Solution:

Step Original Position Analysis Result
Given Mohan = 16th from front Original position -
Removal 1st, 3rd, 5th, 7th, 9th, 11th, 13th, 15th removed Every alternate from front 8 people removed before Mohan
New Position Original 16th position 16 - 8 = 8 8th from front
Verify Remaining: 2,4,6,8,10,12,14,[16-Mohan] Count positions ✓ 8th position

Answer: 8th from front


🔄 3. Ranking in Rows

📌 Type 1: Single Row Arrangement

Understanding left and right positions in a straight line.


🎯 Position Formulas

Formula Application Example
Total = Left + Right - 1 Finding total in row Person is 5th from left, 8th from right
Left Position = Total - Right + 1 Finding left position Total 20, 6th from right = ? from left
Right Position = Total - Left + 1 Finding right position Total 30, 10th from left = ? from right

✏️ Example 4: Row Arrangement

Problem: In a row of children, Ajay is 9th from the left and 15th from the right. How many children are there?

Step-by-Step Solution:

Step Information Calculation Result
Given Position from left 9 -
Given Position from right 15 -
Formula Total = L + R - 1 9 + 15 - 1 23 children

Visual:

Left → 1,2,3,4,5,6,7,8,[9-Ajay],10,11,12,13,14,15,16,17,18,19,20,21,22,23 ← Right
       ←―― 9 from left ――→ AJAY ←―――――― 15 from right ――――――→

Answer: 23 children


📌 Type 2: Two Rows (Facing Each Other)

When two rows face each other, opposite positions matter.


✏️ Example 5: Facing Rows

Problem: Two rows of students are facing each other. Row 1 has 25 students, Row 2 has 25 students. If a student in Row 1 is 10th from the left, which position student from Row 2 is directly facing him from the right side of Row 2?

Step-by-Step Solution:

Step Analysis Calculation Result
Row 1 10th from left Given -
Row 2 Facing arrangement Mirror position -
Logic Same position number If R1 is 10th from left, R2 facing = 10th from right 10th from right
Formula Position remains same Direct opposite

Visual:

Row 1:  1  2  3  4  5  6  7  8  9 [10] 11 12 ... 25 (Left to Right)
        ↕  ↕  ↕  ↕  ↕  ↕  ↕  ↕  ↕  ↕  ↕  ↕     ↕
Row 2: 25 24 23 22 21 20 19 18 17[16] 15 14 ... 1  (Right to Left)

Answer: 10th from right in Row 2


🎖️ 4. Ranking Based on Performance

📌 Performance Comparison Problems

When rankings are based on scores, marks, or achievements.


✏️ Example 6: Comparative Ranking

Problem: In a class of 50 students:

  • A ranks 20th from top
  • B ranks 25th from top
  • How many students are between A and B?

Step-by-Step Solution:

Step Information Calculation Result
Given A = 20th from top Position A -
Given B = 25th from top Position B -
Positions 20, 21, 22, 23, 24, 25 Count between -
Between A & B 25 - 20 - 1 Exclude A and B 4 students

Visual:

Rank: ... 20[A] 21 22 23 24 25[B] ...
           ↑               ↑
         (4 students between them)

Formula: Students between = |Rank₁ - Rank₂| - 1

Answer: 4 students between A and B


5. Time Sequence

What is Time Sequence?

Arranging events, activities, or periods in chronological order based on time.


📅 Types of Time Sequence Problems

Type Description Example
Day Sequence Order of days in a week Monday, Tuesday, Wednesday...
Month Sequence Order of months in a year January, February, March...
Event Sequence Chronological order of events Birth → School → College → Job
Age Comparison Comparing ages of people Oldest to youngest
Time Calculation Finding past/future dates What day was 3 days ago?

📆 6. Day and Date Problems

📌 Days of the Week

Day Number Position Shorthand
Monday 1 1st day Mon
Tuesday 2 2nd day Tue
Wednesday 3 3rd day Wed
Thursday 4 4th day Thu
Friday 5 5th day Fri
Saturday 6 6th day Sat
Sunday 7 7th day (or 0) Sun

🔢 Day Calculation Formula

Formula Application Example
Days forward = Current day + n (mod 7) Finding future day Today is Monday, what day after 10 days?
Days backward = Current day - n (mod 7) Finding past day Today is Friday, what day 5 days ago?
Week cycle = 7 days Repeating pattern Every 7 days, same day repeats

✏️ Example 7: Finding Future Day

Problem: If today is Wednesday, what day will it be 25 days from now?

Step-by-Step Solution:

Step Information Calculation Result
Given Today = Wednesday Day 3 -
Days ahead 25 days Given -
Week calculation 25 ÷ 7 3 weeks + 4 days Remainder = 4
New day Wednesday + 4 days Wed → Thu → Fri → Sat → Sun Sunday

Formula: (Current Day Number + Days Forward) mod 7

Calculation:

Wednesday = 3
25 days = 3 weeks (21 days) + 4 days
3 + 4 = 7 = Sunday (or Day 0)

Answer: Sunday


✏️ Example 8: Finding Past Day

Problem: If today is Saturday, what day was it 17 days ago?

Step-by-Step Solution:

Step Information Calculation Result
Given Today = Saturday Day 6 -
Days ago 17 days back Given -
Week calculation 17 ÷ 7 2 weeks + 3 days Remainder = 3
Past day Saturday - 3 days Sat → Fri → Thu → Wed Wednesday

Calculation:

Saturday = 6
17 days ago = 2 weeks (14 days) + 3 days
6 - 3 = 3 = Wednesday

Answer: Wednesday


📅 7. Month and Year Sequence

📌 Months of the Year

Month Number Days Quarter
January 1 31 Q1
February 2 28/29 Q1
March 3 31 Q1
April 4 30 Q2
May 5 31 Q2
June 6 30 Q2
July 7 31 Q3
August 8 31 Q3
September 9 30 Q3
October 10 31 Q4
November 11 30 Q4
December 12 31 Q4

🎯 Month Memory Trick

Months Days Memory Trick
30 Days Apr, Jun, Sep, Nov "30 days has September, April, June, and November"
31 Days Jan, Mar, May, Jul, Aug, Oct, Dec Use knuckle method (peaks = 31)
28/29 Days February only Leap year = 29, Normal = 28

✏️ Example 9: Month Sequence

Problem: If March is the 3rd month, which month comes 5 months after March?

Step-by-Step Solution:

Step Information Calculation Result
Given March = Month 3 Starting point -
Months ahead 5 months Given -
Calculation 3 + 5 8 Month 8
Month name 8th month August August

Answer: August


🎂 8. Age-Based Sequencing

📌 Age Comparison Problems

Understanding relative ages and time gaps.


✏️ Example 10: Age Ranking

Problem:

  • A is older than B by 3 years
  • B is older than C by 2 years
  • C is older than D by 4 years

Arrange them from oldest to youngest.

Step-by-Step Solution:

Person Age Relation Relative Age Rank
D Youngest (base) 0 years 4th (Youngest)
C D + 4 years 4 years 3rd
B C + 2 years 6 years 2nd
A B + 3 years 9 years 1st (Oldest)

Visual Age Line:

D (0) → C (4) → B (6) → A (9)
Youngest ←――――――――――――――→ Oldest

Answer: A B C D (Oldest to Youngest)


🎓 9. Problem-Solving Strategy

6-Step Approach for Ranking & Time Sequence 📝

Step Action Details Example
Step 1 Identify Problem Type Ranking (top/bottom), Row, Time, Age? "7th from top, 28th from bottom" = Ranking
Step 2 List Given Information Write all positions, totals, dates Total = ?, Rt = 7, Rb = 28
Step 3 Choose Correct Formula Select appropriate formula Total = Rt + Rb - 1
Step 4 Calculate Step-by-Step Show each calculation clearly 7 + 28 - 1 = 34
Step 5 Draw Diagram (if needed) Visual representation helps Draw number line with positions
Step 6 Verify Answer Check if answer makes logical sense 7 + 28 - 1 = 34 ✓

📝 10. Practice Problems

Set A: Basic Ranking Questions 🎯


Q# Question Options
Q1 In a class of 45 students, Ram ranks 15th from the top. What is his rank from the bottom? A) 30brB) 31brC) 32brD) 29

Solution Table:

Step Given Formula Calculation
Total (T) 45 students - -
Rank from top (Rt) 15 - -
Rank from bottom (Rb) ? Rb = T - Rt + 1 45 - 15 + 1 = 31

Answer: B) 31


Q# Question Options
Q2 Mohan is 12th from the left and 18th from the right in a row. How many people are there? A) 28brB) 29brC) 30brD) 31

Solution Table:

Step Information Calculation Result
Left position 12 Given -
Right position 18 Given -
Total L + R - 1 12 + 18 - 1 29

Answer: B) 29


Set B: Time Sequence Questions


Q# Question Options
Q3 If today is Monday, what day will it be 16 days from now? A) TuesdaybrB) WednesdaybrC) ThursdaybrD) Friday

Solution Table:

Step Information Calculation Result
Today Monday (Day 1) - -
Days forward 16 days 16 ÷ 7 = 2 weeks + 2 days Remainder = 2
New day Monday + 2 Mon → Tue → Wed Wednesday

Answer: B) Wednesday


Q# Question Options
Q4 If today is Friday, what day was it 20 days ago? A) MondaybrB) TuesdaybrC) SaturdaybrD) Sunday

Solution Table:

Step Information Calculation Result
Today Friday (Day 5) - -
Days back 20 days 20 ÷ 7 = 2 weeks + 6 days Remainder = 6
Past day Friday - 6 Fri → Thu → Wed → Tue → Mon → Sun → Sat Saturday

Answer: C) Saturday


Set C: Advanced Mixed Questions 🔥


Q# Question Options
Q5 In a class, A ranks 10th from top and B ranks 15th from bottom. If there are 5 students between them, how many total students? A) 28brB) 29brC) 30brD) 31

Solution Table:

Step Information Analysis Calculation
A from top 10th Given -
B from bottom 15th Given -
Between A & B 5 students Given -
Total A's rank + Between + B's rank 10 + 5 + 15 30 students

Answer: C) 30


Q# Question Options
Q6 If June 15th is a Monday, what day of the week is June 25th? A) TuesdaybrB) WednesdaybrC) ThursdaybrD) Friday

Solution Table:

Step Information Calculation Result
June 15 Monday Given -
June 25 ? 25 - 15 = 10 days forward -
Days calculation 10 ÷ 7 1 week + 3 days Remainder = 3
New day Monday + 3 Mon → Tue → Wed → Thu Thursday

Answer: C) Thursday


Q# Question Options
Q7 In a row of 60 people, A is 20th from left. After interchanging positions with B who is 30th from right, what is A's new position from left? A) 30brB) 31brC) 32brD) 29

Solution Table:

Step Analysis Calculation Result
A's original 20th from left Given -
B's original 30th from right Given -
B's position from left Total - Right + 1 60 - 30 + 1 = 31 B is 31st from left
After interchange A takes B's position A moves to 31st from left 31st from left

Answer: B) 31


Q# Question Options
Q8 A is older than B by 5 years. B is younger than C by 3 years. If C is 25 years old, what is A's age? A) 22brB) 23brC) 27brD) 28

Solution Table:

Person Age Relation Calculation Age
C 25 years Given 25
B C - 3 years 25 - 3 22
A B + 5 years 22 + 5 27

Answer: C) 27 years


Q# Question Options
Q9 In a merit list of 100 students, P is 15 ranks ahead of Q. If Q's rank is 40th from bottom, what is P's rank from top? A) 45brB) 46brC) 47brD) 44

Solution Table:

Step Information Calculation Result
Total students 100 Given -
Q from bottom 40th Given -
Q from top 100 - 40 + 1 61st from top -
P is 15 ahead Better rank (lower number) 61 - 15 46th from top

Answer: B) 46


Q# Question Options
Q10 If 1st January 2020 was a Wednesday, what day was 1st March 2020? (2020 is a leap year) A) SaturdaybrB) SundaybrC) MondaybrD) Tuesday

Solution Table:

Step Month Days Calculation
January 1st to 31st 31 days -
February 1st to 29th 29 days (leap year) -
Total days Jan + Feb 31 + 29 = 60 days -
Weeks 60 ÷ 7 8 weeks + 4 days Remainder = 4
Starting day Wednesday - -
1st March Wed + 4 days Wed → Thu → Fri → Sat → Sun Sunday

Answer: B) Sunday


🎯 11. Quick Reference Charts

Ranking Formulas Summary

What to Find Formula When to Use
Total Rt + Rb - 1 Given both ranks (top & bottom)
Rank from Top T - Rb + 1 Given total and rank from bottom
Rank from Bottom T - Rt + 1 Given total and rank from top
Students Between |Rank₁ - Rank₂| - 1 Finding gap between two ranks
Position in Row L + R - 1 Given left and right positions

Day Calculation Quick Reference

Days Forward/Back Action Formula
Finding Future Day Add days, divide by 7 (Current day + Days) mod 7
Finding Past Day Subtract days, divide by 7 (Current day - Days) mod 7
Same Day Repeat Every 7 days Multiples of 7 = same day

Month Days Memory Table

Month Type Months Days Memory Aid
31 Days Jan, Mar, May, Jul, Aug, Oct, Dec 31 Knuckle peaks
30 Days Apr, Jun, Sep, Nov 30 Between knuckles
Special February 28/29 Leap year check

🏆 12. Key Takeaways & Pro Tips

# Tip Why It Matters
1 🔢 Remember the "-1" rule Avoid double counting in rank formulas
2 📊 Draw position diagrams Visual aids prevent confusion
3 Master the 7-day cycle Every 7 days, same day repeats
4 📅 Know month days by heart Essential for date calculations
5 Always verify with formula Check answer makes logical sense
6 🎯 Identify problem type first Ranking vs Time vs Age sequence
7 📝 Write down all given info Don't solve in head for complex problems
8 🔄 Use remainder in day problems Modulo 7 is your best friend

📚 13. Common Mistakes to Avoid

Mistake Why It's Wrong Correct Approach
Forgetting -1 in rank formula Counts person twice Always use Rt + Rb - 1
Not using remainder Wrong day calculation Always divide by 7 and use remainder
Confusing left with right Opposite positions Draw diagram to clarify
Ignoring leap year February has 29 days Check if leap year (divisible by 4)
Adding instead of subtracting Wrong direction in past days Backward = subtract, Forward = add
Mixing up "between" Including endpoints Between = exclude both endpoints

💡 14. Advanced Tips & Tricks

Shortcut for Day Calculations

Days Ahead Shortcut Example
7, 14, 21, 28... Same day Monday + 14 days = Monday
1 day Next day Monday + 1 = Tuesday
6 days Previous day Monday + 6 = Sunday (one day before)

Leap Year Quick Check

Rule Condition Example
Divisible by 4 Leap year 2020 ÷ 4 = 505 ✓ (Leap)
Century year Must be divisible by 400 2000 ÷ 400 = 5 ✓ (Leap), 1900 ✗ (Not)
February days 29 in leap, 28 in normal 2020 = 29 days, 2021 = 28 days

Up to Top