Clock, Calendar, Mirror & Water Images - Complete SSC CGL Guide
What are Clock, Calendar, Mirror & Water Images? These are reasoning questions that test your understanding of time, dates, and spatial visualization. Clock problems involve angles and time calculations, calendar questions test day-date relationships, while mirror/water images test visual reasoning.
Clock showing 4:00:00 - What's the angle between hands?
Mirror Image
Laterally inverted
Left ↔ Right
Water Image
Vertically inverted
Top ↔ Bottom
Difference between Mirror and Water Images - AMBULANCE is actually written for mirror reading!
Pro Tip – The 3-Second Rule for Clock Angles!
Formula: |30H - 5.5M| = Angle between hands
Where H = hour, M = minute
Example: At 4:30, angle = |30×4 - 5.5×30| = |120 - 165| = 45°
Visit SKY Practice for 300+ Clock, Calendar, Mirror & Water Image questions with instant checking.
1. Clock Reasoning Basics
Understanding Clock Mechanics: A clock has hour, minute, and second hands moving at different speeds. The relative speeds create interesting angle problems.
Clock Fundamentals
Clock Components & Speeds
A clock has 12 hours, 60 minutes, 60 seconds. Each hand moves at different angular speeds creating angle problems.
Hour Hand Movement
• Per minute: 0.5° per minute
• Complete rotation: 360° in 12 hours
• Relation: 1 hour = 30°
Example: From 12 to 3 = 3 hours = 90°
Minute Hand Movement
• Per minute: 6° per minute
• Complete rotation: 360° in 60 minutes
• Relation: 1 minute = 6°
Example: 15 minutes = 15×6 = 90°
Relative Speed
• Calculation: (6° - 0.5°) = 5.5° per minute
• Meeting times: Every 65⁵⁄₁₁ minutes
• Logic: Minute hand gains 5.5° on hour hand each minute
Key: This 5.5° is crucial for all clock problems
Angle Formula
θ = |30H - 5.5M|
Where H = hour, M = minute
Alternative:
θ = |(60H - 11M)/2|
Example: 3:20
θ = |30×3 - 5.5×20|
= |90 - 110| = 20°
SSC Shortcut: Clock Angle Quick Calculation
For exact hours (XX:00): Angle = 30 × hour (if ≤6) or 360 - (30×hour) (if >6)
For XX:30: Angle = |30×hour - 165| (since 5.5×30 = 165)
For any time: Use formula |30H - 5.5M|, round if needed
Remember: Angle is always ≤180° (take smaller angle)
Check: If answer >180, subtract from 360
Practice: 2:20 = |60 - 110| = 50°, 8:40 = |240 - 220| = 20°
Solved Example: Basic Clock Angle
θ = |30H - 5.5M|
Here H = 7, M = 20
θ = |30×7 - 5.5×20|
= |210 - 110|
= 100°
Method 2: Step by step
Step 1: Position of hour hand at 7:00
At 7:00 exactly, hour hand at 7×30 = 210° from 12 (or 150° from 12 in other direction)
But easier: Each hour = 30°, so 7 hours = 210° from 12
Step 2: Movement of hour hand in 20 minutes
Hour hand moves 0.5° per minute
In 20 minutes, moves 20×0.5 = 10°
So at 7:20, hour hand at 210° + 10° = 220° from 12
Step 3: Position of minute hand at 20 minutes
Minute hand at 20 minutes = 20×6 = 120° from 12
Step 4: Angle difference
Difference = |220° - 120°| = 100°
Step 5: Check if >180°
100° < 180°, so answer is 100°
Step 6: Verify with common sense
At 7:20, minute hand at 4 (120°), hour hand slightly past 7
Between 4 and 7 is 3 hours = 90°, plus hour hand moved past 7
Hour hand moved 10° past 7 (since 20 min = ⅓ hour)
So angle = 90° + 10° = 100° ✓
Final Answer: 100°
2. Clock Angle Problems & Tricks
Advanced Clock Problems: These include when hands coincide, are perpendicular, are in straight line, or reflect/time gain-loss problems.
Special Clock Positions
When Clock Hands Meet Specific Angles
Hands coincide (0°), are perpendicular (90°), are in straight line (180°), or at other specific angles at particular times.
Clock Problem Frequency in SSC CGL
Hands Coincide (0°)
Formula: Minutes past H = (60H)/11
First time: After 12:00, at 12:00 exactly
Next: 1:05⁵⁄₁₁, 2:10¹⁰⁄₁₁, 3:16⁴⁄₁₁, etc.
Derivation:
0 = |30H - 5.5M|
⇒ 30H = 5.5M
⇒ M = (30H)/5.5 = (60H)/11
Hands Perpendicular (90°)
Formula: M = (60H ± 180)/11
First time after 12: 12:16⁴⁄₁₁ and 12:49¹⁄₁₁
Logic: 30H - 5.5M = ±90
Example: 3:00 to 3:30
First 90° at 3:00 exactly? No, that's 90° but minute at 12
Actually at 3:00, angle = 90° ✓
Next after 3:00: M = (60×3 - 180)/11 = 0 (that's 3:00)
Or (60×3 + 180)/11 = 360/11 = 32⁸⁄₁₁
Straight Line (180°)
Formula: M = (60H - 360)/11
Actually: 30H - 5.5M = ±180
So M = (30H ± 180)/5.5 = (60H ± 360)/11
Example: Between 5 and 6
M = (60×5 - 360)/11 = (300-360)/11 = -60/11 (not valid)
M = (60×5 + 360)/11 = 660/11 = 60 (that's 6:00)
So between 5 and 6, no exact opposite?
Actually at 6:00 exactly, hands are opposite ✓
Mirror/Water Time
Water time: 18:30 - given time (or 6:30 PM)
Example: Mirror of 4:20
11:60 - 4:20 = 7:40
Check: Look at clock in mirror at 4:20, you'll see 7:40
Water time: Less common
18:30 - 4:20 = 14:10 = 2:10 PM
1 Defective Clock Problems
• Fast clock gains time
• Slow clock loses time
• Real time calculation needed
Formula:
Real time interval = (Fast clock time × 60) / (60 + gain per hour)
Or = (Slow clock time × 60) / (60 - loss per hour)
Example: Clock gains 5 min per hour
Shows 12 noon after running from correct time at 6 AM
Real time = (6 × 60) / (60 + 5) × 60? Wait...
Actually: In 60 min real, clock shows 65 min
So when clock shows 6 hours (360 min),
Real time = (360 × 60) / 65 = 332.3 min = 5 hr 32.3 min
So real time = 11:32 AM, not 12 noon
2 Meeting Times Formula
First time after T: M = (60 × H)/11 minutes past T
Hands are perpendicular:
M = (60H ± 180)/11
Hands are in straight line:
M = (60H ± 360)/11
At any angle θ:
M = (60H ± 2θ)/11
(Derived from 30H - 5.5M = ±θ)
Remember: Use + for one position, - for other (two times per angle usually)
Solved Example: Hands Coincide Problem
Minutes past H = (60H)/11
Here H = 7
M = (60 × 7)/11 = 420/11 = 38²⁄₁₁ minutes
So time = 7:38²⁄₁₁ (7:38 and 2/11 minutes)
Method 2: Using relative speed
Step 1: At 7:00, hour hand at 210°, minute hand at 0°
Angle difference = 210°
Step 2: Relative speed = 5.5° per minute
Minute hand needs to cover 210° more than hour hand
Time = Distance/Speed = 210°/5.5° per minute
= 210/5.5 = 420/11 = 38²⁄₁₁ minutes
Step 3: Add to 7:00
7:00 + 38²⁄₁₁ minutes = 7:38²⁄₁₁
Method 3: Verification
At 7:38, minute hand at 38×6 = 228°
Hour hand at 210° + 38×0.5 = 210° + 19° = 229°
Close but not exactly (1° difference)
At exact time 7:38²⁄₁₁:
Minute: (38²⁄₁₁)×6 = (420/11)×6 = 2520/11 = 229¹⁄₁₁°
Hour: 210 + (420/11)×0.5 = 210 + 210/11 = 210 + 19¹⁄₁₁ = 229¹⁄₁₁°
Perfect match!
Final Answer: 7:38²⁄₁₁ (7 hours 38 and 2/11 minutes)
Solved Example: Mirror Time Problem
Mirror time formula: Actual time = 11:60 - Mirror time
Here mirror time = 8:20
Convert to minutes: 8:20 = 8×60 + 20 = 500 minutes
11:60 = 11×60 + 60 = 720 minutes
Difference = 720 - 500 = 220 minutes
220 minutes = 3 hours 40 minutes = 3:40
So actual time = 3:40
Method 2: Logical reasoning
Step 1: Mirror inverts left and right
In mirror, 12 becomes 12, 6 becomes 6, but 3 becomes 9, 9 becomes 3
So mirror image of time is like seeing from behind
Step 2: Quick trick: Subtract from 11:60
11:60 - 8:20 = (11-8):(60-20) = 3:40
But careful: 60-20=40 ✓
Step 3: Verify by imagining
Imagine clock showing 3:40
Hour hand between 3 and 4, closer to 4 (since 40 min)
Minute hand at 8 (40 min = 8 positions)
In mirror, 3:40 becomes:
Hour hand between 8 and 9 (mirror of between 3 and 4)
Minute hand at 4 (mirror of 8)
That's 8:20 ✓
Method 4: Alternative formula
Actual time = (23:60 - Mirror time) mod 12
23:60 = 23×60 + 60 = 1440 minutes
Mirror time = 500 minutes
Difference = 1440 - 500 = 940 minutes
940 mod 720 (12 hours) = 220 minutes = 3:40
(Same result)
Final Answer: 3:40
3. Calendar Reasoning Basics
Calendar Problems: Finding day of week for given date, calculating number of odd days, leap year calculations, and date patterns.
Calendar Fundamentals
Understanding Calendar Structure
Year has 365 days (366 in leap year). Week has 7 days. Odd days are extra days beyond complete weeks.
Sample calendar showing odd days concept
Odd Days Concept
Example: 10 days = 1 week + 3 days → 3 odd days
Calculation: Divide days by 7, remainder = odd days
Key values:
• 365 days = 52 weeks + 1 day → 1 odd day
• 366 days = 52 weeks + 2 days → 2 odd days
• 100 years = 76 ordinary + 24 leap = 124 odd days
(124 mod 7 = 5 odd days)
Leap Year Rules
Rule 2: Divisible by 100 → Not leap year
Rule 3: Divisible by 400 → Leap year
Examples:
• 2000: Div by 400 → Leap ✓
• 1900: Div by 100 but not 400 → Not leap
• 2024: Div by 4 → Leap ✓
• 2100: Div by 100 but not 400 → Not leap
Century years: Only if divisible by 400
Odd Days for Periods
1 leap year: 2 odd days
100 years: 5 odd days
200 years: 3 odd days (5+5=10 mod7=3)
300 years: 1 odd day (5+5+5=15 mod7=1)
400 years: 0 odd days (5×4=20 mod7=6? Wait)
Actually 400 years = 303 ordinary + 97 leap
Odd days = 303×1 + 97×2 = 303+194=497
497 mod7 = 497÷7=71 rem0 → 0 odd days ✓
Day Codes (Important!)
Monday: 1
Tuesday: 2
Wednesday: 3
Thursday: 4
Friday: 5
Saturday: 6
Month codes:
Jan: 0 (1 in leap), Feb: 3 (4), Mar: 3,
Apr: 6, May: 1, Jun: 4, Jul: 6,
Aug: 2, Sep: 5, Oct: 0, Nov: 3, Dec: 5
SSC Shortcut: Century Anchor Days
1700-1799: Friday anchor (5)
1800-1899: Wednesday anchor (3)
1900-1999: Tuesday anchor (2)
2000-2099: Sunday anchor (0)
2100-2199: Friday anchor (5)
Pattern: -2 days per century (400 year cycle)
Use: Find day for any date quickly using anchor day + doomsday rule
Solved Example: Basic Calendar Problem
Step 1: Years before 1947
1600-1699: 100 years → 5 odd days
1700-1799: 100 years → 5 odd days
1800-1899: 100 years → 5 odd days
1900-1946: 47 years
Step 2: Calculate 1900-1946
1900-1900: 1 year (1900 not leap)
1901-1946: 46 years
Leap years in 1901-1946:
1904,1908,1912,1916,1920,1924,1928,1932,1936,1940,1944
That's 11 leap years
Ordinary years = 46 - 11 = 35
Odd days = 35×1 + 11×2 = 35 + 22 = 57
57 mod7 = 57÷7=8 rem1 → 1 odd day
Step 3: Add century odd days
1600-1699: 5
1700-1799: 5
1800-1899: 5
Total centuries = 5+5+5=15 → 15 mod7=1
Plus 1900-1946 = 1 odd day
Total so far = 1+1=2 odd days
Step 4: Days in 1947 till Aug 15
Jan: 31, Feb: 28 (1947 not leap), Mar:31, Apr:30, May:31, Jun:30, Jul:31, Aug:15
Total = 31+28+31+30+31+30+31+15 = 227 days
Odd days = 227 mod7 = 227÷7=32 rem3 → 3 odd days
Step 5: Total odd days
Centuries: 2
1947 days: 3
Total = 2+3=5 odd days
Step 6: Convert to day
0=Sun,1=Mon,2=Tue,3=Wed,4=Thu,5=Fri,6=Sat
5 odd days = Friday
Method 2: Using anchor day (faster)
Step 1: 1900-1999 anchor = Tuesday (2)
Step 2: Years from 1900 to 1947 = 47 years
Leap years = 11 (as above)
Ordinary = 36
Total odd days = 36×1 + 11×2 = 36+22=58
58 mod7 = 58÷7=8 rem2 → 2 odd days
Step 3: Days till Aug 15 = 227 (as above)
227 mod7 = 3 odd days
Step 4: Total = Anchor(2) + years(2) + days(3) = 7
7 mod7 = 0 = Sunday? Wait that gives Sunday, but we know it's Friday
Let's recalculate...
Actually simpler method:
Use formula: Day = (Date + Month code + Year code + Century code) mod7
For 15 Aug 1947:
Date = 15
Month code for Aug = 2
Year code for 47 = (47 + ⌊47/4⌋) mod7 = (47+11) mod7 = 58 mod7 = 2
Century code for 1900s = 0
Total = 15+2+2+0=19
19 mod7 = 19÷7=2 rem5 → 5 = Friday ✓
Historical fact: 15 Aug 1947 was indeed Friday
Final Answer: Friday
4. Day Calculation Techniques
Advanced Calendar Problems: Finding repeated calendar years, calculating days between dates, and solving complex day-of-week problems.
Advanced Day Calculations
Calendar Repetition Patterns
Calendars repeat after certain years. Ordinary years repeat after 6, 11, or 28 years. Leap years repeat after 28 years.
Day codes for calculations
1 Calendar Repetition Rules
Example: 2001 same as 2007 (both ordinary)
Leap year: After 28 years (if within same century pattern)
Example: 2000 same as 2028 (both leap)
General rule: Add odd days = 0
• After 11 years: 11 ordinary years = 11 odd days, but leap years change
• After 28 years: Complete cycle for 1901-2099 period
• After 400 years: Exact repetition (0 odd days)
Check: 2001 calendar = 2007, 2018, 2029 (11 year gaps with adjustment)
2 Zeller's Congruence (Fast Formula)
Where:
• h = day of week (0=Sat,1=Sun,...,6=Fri)
• q = day of month
• m = month (3=Mar,...,12=Dec,13=Jan,14=Feb)
• K = year of century (YY)
• J = zero-based century (⌊year/100⌋)
Example: 15 Aug 1947
q=15, m=6 (Aug=8 → 8+12=20? Wait formula uses 3=Mar,...)
Actually: Jan=13,Feb=14,Mar=3,Apr=4,...,Dec=12
So Aug=8 (already correct 3-12 for Mar-Dec)
K=47, J=19
h = (15 + ⌊13×9/5⌋ + 47 + ⌊47/4⌋ + ⌊19/4⌋ - 2×19) mod7
= (15 + ⌊117/5⌋ + 47 + 11 + 4 - 38) mod7
= (15 + 23 + 47 + 11 + 4 - 38) mod7
= (62) mod7 = 62÷7=8 rem6 → 6 = Friday ✓
Note: Complex but reliable for any date
Solved Example: Days Between Dates
March: 31 days, from 15th to 31st = 16 days (31-15=16)
April: 30 days
May: 31 days
June: 30 days
July: 31 days
August: up to 15th = 15 days
Total = 16 + 30 + 31 + 30 + 31 + 15
= 16 + 30 = 46
46 + 31 = 77
77 + 30 = 107
107 + 31 = 138
138 + 15 = 153 days
Method 2: Using day numbers
Day number of Aug 15 = 227th day (as calculated earlier)
Day number of Mar 15 in non-leap year:
Jan:31 + Feb:28 = 59, plus 15 = 74th day
Difference = 227 - 74 = 153 days ✓
Method 3: Quick calculation
Mar 15 to Apr 15 = 31 days (March has 31)
Apr 15 to May 15 = 30 days
May 15 to Jun 15 = 31 days
Jun 15 to Jul 15 = 30 days
Jul 15 to Aug 15 = 31 days
But careful: From Mar 15 to Apr 15 is actually:
Mar 15-31: 16 days + Apr 1-15: 15 days = 31 days ✓
Similarly others
Total = 31+30+31+30+31 = 153 days
Verification:
Count on calendar: March has 16 days left
April full = 30
May full = 31
June full = 30
July full = 31
August 1-15 = 15
16+30=46, +31=77, +30=107, +31=138, +15=153 ✓
Final Answer: 153 days
5. Mirror Images
Mirror Image Reasoning: Objects appear laterally inverted (left-right reversed) in mirror. Alphabet, numbers, clock times in mirror.
Mirror Image Rules
Understanding Mirror Reflection
Mirror creates lateral inversion - left becomes right, right becomes left. Top and bottom remain same. Some letters appear same in mirror.
Alphabet mirror images - some symmetrical, some change completely
| Type | Mirror Image | Rule | Example |
|---|---|---|---|
| Symmetrical Letters | Same | Vertical symmetry | A, H, I, M, O, T, U, V, W, X, Y |
| Laterally Inverted | Changed | Left-right reversed | B→, C→, D→, E→, F→, etc. |
| Numbers | Some same | 0,1,3,8 same (approx) | 2→, 5→, 6→9, 7→ |
| Clock Times | 11:60 - time | Subtract from 11:60 | 4:20 → 7:40 |
SSC Shortcut: Mirror Image Quick Method
For alphabets: Imagine vertical line in middle, check symmetry
For words: Write backwards and check each letter's mirror form
For clock: Use formula: Mirror time = 11:60 - Actual time
For numbers: 0,1,3,8 remain same; 6 becomes 9, 9 becomes 6
For mixed: Process left to right, replace each character
Practice: "AMBULANCE" is written mirrored on real ambulances!
Solved Example: Mirror Image Problem
Step 1: S in mirror
S is not symmetrical vertically
Mirror of S looks like backward S (still S-like but different)
Actually S becomes something like ∫ (integral symbol)
But in reasoning questions, often they show approximate
Step 2: C in mirror
C becomes reversed C (opens to right instead of left)
Like ) but not exactly
Step 3: I in mirror
I is symmetrical → remains I
Step 4: E in mirror
E becomes reversed E (like ヨ in Japanese)
Actually E becomes something like 山 sideways
Step 5: N in mirror
N becomes reversed N (still N but different)
Actually N becomes И (Cyrillic I)
Step 6: Complete word "SCIENCE"
S→ (mirror S), C→ (mirror C), I→I, E→ (mirror E), N→ (mirror N), C→ (mirror C), E→ (mirror E)
Method 2: Using standard patterns
In SSC, they usually provide options with stylized mirror images
Need to recognize pattern:
• Letters with vertical symmetry: A,H,I,M,O,T,U,V,W,X,Y remain same
• Others get laterally inverted
• For SCIENCE: S,C,E,N not symmetrical, I is symmetrical
So mirror would have I same, others changed
Method 3: Practical approach
Imagine holding word in front of mirror
Or write it on paper and hold up to mirror
Actually: S becomes backward S, C becomes ), I stays I,
E becomes ヨ, N becomes И, C becomes ), E becomes ヨ
So mirror image looks like: )IヨИ)ヨ with S at start
For exam: Look at options, eliminate clearly wrong ones
Options will show various mirror versions
Choose one where I is unchanged, others look mirrored
Note: Exact mirror image depends on font/style
In multiple choice, pick best match
6. Water Images
Water Image Reasoning: Objects appear vertically inverted (upside down) in water reflection. Top becomes bottom, bottom becomes top.
Water Image Rules
Understanding Water Reflection
Water creates vertical inversion - top becomes bottom, bottom becomes top. Left and right remain same. Different from mirror images.
1 Water vs Mirror Difference
• Lateral inversion (left-right swap)
• Top-bottom unchanged
• Example: b becomes d
Water Image:
• Vertical inversion (top-bottom swap)
• Left-right unchanged
• Example: b becomes p
Key difference:
Mirror: b → d (left-right flip)
Water: b → p (upside down)
Clockwise 90° rotation vs 180° rotation
2 Water Image of Alphabets
B, C, D, E, H, I, K, O, X (approximately)
Changed in water:
A becomes ∀ (upside down A)
F becomes (upside down)
G becomes (upside down)
J becomes (upside down)
L becomes (upside down)
M becomes W (actually M upside down = W!)
N becomes (upside down)
P becomes (upside down)
Q becomes (upside down)
R becomes (upside down)
S becomes (still S but upside down)
T becomes (upside down)
U becomes ∩ (upside down U)
V becomes Λ (upside down V)
W becomes M (upside down W = M!)
Y becomes (upside down)
Z becomes (upside down, still Z)
Note: M↔W are water images of each other
Solved Example: Water Image Problem
Step 1: W in water
W upside down becomes M
Step 2: A in water
A upside down becomes ∀ (inverted A)
Step 3: T in water
T upside down is still T (vertically symmetrical)
Actually T upside down is still T ✓
Step 4: E in water
E upside down is still E (horizontally symmetrical)
Actually E has horizontal symmetry, so upside down same
Step 5: R in water
R upside down is not symmetrical
Looks like something
Step 6: Complete word "WATER"
W→M, A→∀, T→T, E→E, R→(inverted R)
So water image looks like "M∀TE" with inverted R
Method 2: Using symmetry
Letters with horizontal symmetry (same when flipped top-bottom):
B, C, D, E, H, I, K, O, X
From WATER: E has horizontal symmetry
T also has horizontal symmetry (T upside down = T)
W becomes M (special case)
A becomes inverted A
R becomes inverted R
For exam: Options will show:
• W changed to M
• A changed to inverted A
• T unchanged
• E unchanged
• R changed to inverted R
Visualization:
Write WATER on paper, turn paper upside down
W becomes M, A becomes ∀, T stays T, E stays E, R becomes something
So answer: M∀TE with last letter inverted R
Final note: Exact representation varies in fonts
Choose option matching this pattern
| Character | Mirror Image | Water Image | Key Difference |
|---|---|---|---|
| A | A (same) | ∀ (inverted) | Mirror same, water inverted |
| B | (mirrored) | B (same) | Water same, mirror changed |
| C | ) (mirrored) | C (same) | Water same, mirror changed |
| M | M (same) | W (inverted) | Mirror same, water becomes W |
| W | W (same) | M (inverted) | Mirror same, water becomes M |
| 3 | E (mirrored) | ε (inverted) | Both change differently |
| 6 | (mirrored) | 9 (inverted) | Water becomes 9 |
| 9 | (mirrored) | 6 (inverted) | Water becomes 6 |
7. SSC Shortcuts & Time Management
Exam Strategy: Clock, calendar, mirror & water image questions can be solved quickly with the right shortcuts.
Time-Saving Techniques
Speed vs Accuracy Balance
In SSC exams, you need to solve these questions in 30-60 seconds each. These techniques help maximize score.
Clock Shortcuts
• Coincide: M = (60H)/11 past H
• Mirror time: 11:60 - given time
• Fast calculation: For XX:30, use |30H - 165|
Memorize:
12:00 → 0°
3:00 → 90°
6:00 → 180°
9:00 → 90° (270°)
Calendar Shortcuts
• Century anchors: 1900=Tue, 2000=Sun
• Month codes: Jan0, Feb3, Mar3, Apr6,...
• Day formula: (D+M+C+Y) mod7
Quick: For 15 Aug 1947:
(15+2+0+2) mod7 = 19 mod7 = 5 = Fri
Image Shortcuts
• Water: Top-bottom swap
• Clock mirror: 11:60 - time
• Symmetry letters: A,H,I,M,O,T,U,V,W,X,Y
Remember:
M↔W are water images
b↔d are mirror images
b↔p are water images
Time Management
• Calendar days: 45 seconds
• Mirror/water: 30 seconds
• Complex problems: 60 seconds max
• If stuck: Guess and move on
Total: Allocate 5-8 minutes for all these questions
SSC Shortcut: Common Exam Patterns
Pattern 1: Clock angle at XX:30 or XX:15
Pattern 2: Day of week for Independence Day (15 Aug) or Republic Day (26 Jan)
Pattern 3: Mirror of word with symmetrical letters (like "TOMATO")
Pattern 4: Water image of word with M/W (like "WOMAN")
Pattern 5: Clock showing mirror time, find actual time
Pattern 6: Repeated calendar after N years
Memory tip: Practice each pattern separately before mixed practice
8. Practice Exercises
Hands-on Practice: Apply what you've learned with these SSC-level questions.
Interactive Practice Questions
Practice Approach
Time yourself: 45 seconds per question. Apply the shortcuts systematically.
Practice Question 1: Clock Angle
Practice Question 2: Mirror Image
Practice Question 3: Calendar Day
SSC Shortcut: Practice Strategy
Daily practice: 5-10 questions daily of each type
Time tracking: Use timer to improve speed
Error analysis: Review mistakes in mirror/water images
Previous papers: Solve last 5 years' SSC questions
Mixed practice: Practice all types randomly
Build speed: Aim to solve each question in 30-45 seconds
Ready to Master Clock, Calendar, Mirror & Water Images?
Access 300+ Clock, Calendar, Mirror & Water Image questions with detailed solutions, instant checking, and time-saving techniques
Start Visual Reasoning PracticeIncludes all types: clock angles, calendar days, mirror images, water images, mixed problems
Frequently Asked Questions
Q1: How many clock/calendar/mirror questions in SSC CGL?
Answer: Typically 4-8 questions in Tier I. These include clock angles (2-3), calendar days (1-2), mirror/water images (1-3).
Q2: What's the fastest way to calculate clock angles?
Answer: Use formula |30H - 5.5M|. For exact half hours (XX:30), use |30H - 165|. For quarter hours, calculate hour hand movement.
Q3: How to remember mirror vs water images?
Answer: Mirror = left-right swap (like looking in mirror). Water = top-bottom swap (like reflection in water). M becomes W in water, b becomes d in mirror, b becomes p in water.
Q4: What are the symmetrical letters for mirror images?
Answer: A, H, I, M, O, T, U, V, W, X, Y remain same in mirror. These have vertical symmetry.
Q5: How to calculate day for any date quickly?
Answer: Use: (Date + Month code + Year code + Century code) mod 7. Memorize month codes and century anchors (1900=Tue=2, 2000=Sun=0).
Q6: Best way to improve speed for these questions?
Answer: Practice with timer, memorize formulas, learn shortcuts, solve previous papers, focus on weak areas (usually mirror/water images).
Final Exam Strategy for Clock/Calendar/Mirror Questions
Time Allocation: Total 5-8 minutes for all these questions.
Priority Order: 1) Clock angles (easiest), 2) Calendar days (medium), 3) Mirror images (visual), 4) Water images (hardest).
Accuracy Check: For clock angles, verify if >180°, subtract from 360°. For mirror images, check symmetrical letters.
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