Mirror Images

Mirror Images

🟢 Lite — Quick Review (1h–1d)

Mirror Images questions test your ability to visualise how an object or letter/number appears when reflected in a plane mirror. In SSC CGL Tier-I, this topic appears in the Non-Verbal Reasoning section. There are two main types: (1) finding the mirror image of a given figure, and (2) identifying which figure matches the mirror image of a given object.

Key Principle: A plane mirror produces a lateral inversion (left-right reversal) of the original object. The object and its mirror image are symmetrical along the mirror line.

Rules for Mirror Images:

Rule 1 — Letters and Numbers: The mirror image of a letter/number is its horizontally flipped version. For capital letters:

• Letters symmetric about the vertical axis (A, H, I, M, O, T, U, V, W, X, Y) look the same in their mirror image.
• Letters NOT symmetric (B, C, D, E, F, G, J, K, L, N, P, Q, R, S, Z) get laterally inverted — B becomes a reversed B (not a valid letter), C becomes a reversed C, etc.

Rule 2 — Clockwise vs Anticlockwise Direction: If an arrow or sequence of letters/numbers is arranged in a clockwise direction in the original, its mirror image will appear anticlockwise.

Rule 3 — Mirror Line Position:

• When a figure is placed to the right of the mirror line, its mirror image appears to the left.
• The mirror never flips the top-to-bottom orientation — only the left-to-right orientation.

Rule 4 — Clock Times: If the time shown in a mirror is T, the actual time = 12:00 − T (for times between 00:01 and 11:59). Example: Mirror shows 3:00 → actual time is 9:00.

Key Symmetric Letters (Same in Mirror): A, H, I, M, O, T, U, V, W, X, Y

Key Asymmetric Letters (Change in Mirror): B → looks like reversed 8 / q-like shape C → looks like reversed C D → looks like reversed D E → looks like reversed 3 / m-like shape J → looks like reversed L K → looks like a sideways T L → looks like reversed J P → looks like reversed P R → looks like reversed R (Я-like) S → looks like a reversed S (Ƨ) — it does change in a mirror

⚡ Exam Tip: When you see a capital letter question, immediately check if it belongs to the symmetric group (A, H, I, M, O, T, U, V, W, X, Y). If it does, the answer is the letter itself. If not, draw the letter’s mirror image mentally. For clock mirror questions, always use the formula: Actual time = 12:00 − Mirror time.

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🟡 Standard — Regular Study (2d–2mo)

Mirror Images — SSC CGL Study Guide

Core Concept: A mirror image is formed by reflection in a plane mirror. The fundamental rule is that the mirror reverses the perpendicular (left-right) axis while keeping the parallel (top-bottom) axis unchanged. In SSC CGL, mirror image questions appear in Tier-I (typically 1 question, 2 marks) and test combinations of letters, numbers, figures, and clock times.

Worked Examples:

Example 1 — Capital Letters: Find the mirror image of the word ALPHA when reflected in a vertical mirror placed to its right.

The mirror reverses the left-right axis, so the letters are read in reverse order — the last letter A appears nearest the mirror line and the first letter A appears furthest from it. Each letter is then individually flipped left-right.

Process the word letter by letter, applying the symmetry test:

• A → A (vertically symmetric, unchanged)
• L → reversed-L, a hook shape that resembles a turned J
• P → reversed-P, an open shape resembling a backwards P (d-like)
• H → H (vertically symmetric, unchanged)
• A → A (vertically symmetric, unchanged)

Because three of the five letters (A, H, A) are vertically symmetric, only L and P visibly change shape, while the whole word is also read in reverse order. The correct answer is the option that shows the original A–H–reversed-P–reversed-L–A sequence, i.e. the option whose middle letters appear as flipped versions of P and L with the three A/H letters unchanged. Answer: option (c), where the flipped P and L are rendered with their mirrored glyphs.

Takeaway: Identify the symmetric letters first (they never change), then flip only the asymmetric ones, and remember the reading order reverses left to right.

Example 2 — Clock Mirror: A clock shows 4:30 in a mirror placed on the wall opposite. What is the actual time?

• Mirror time = 4:30
• Actual time = 12:00 − 4:30 = 7:30 Answer: 7:30

Example 3 — Figure Mirror Image: A figure is placed to the left of a vertical mirror line. Which option shows the correct mirror image?

• The figure’s left side appears on the right in the mirror.
• The mirror line itself is never shown in the image (the image appears on the opposite side).
• The top and bottom remain in the same positions.
• The right side of the original appears on the left side of the image.

Example 4 — Number Mirror: What is the mirror image of 257?

• 2 → a reversed 2
• 5 → a reversed 5
• 7 → a reversed 7 (resembles a turned L in many fonts) Answer: The image reads as reversed 7, reversed 5, reversed 2 — the digits flip individually and the reading order reverses.

Common Student Mistakes:

• Wrongly assuming S (or Z) stays the same in a mirror — both actually flip to a reversed S (Ƨ) and reversed Z, because they have only rotational, not reflective, symmetry.
• Forgetting that the mirror never changes the top-bottom orientation.
• Mixing up clockwise and anticlockwise direction changes.
• Forgetting to subtract from 12:00 for clock mirror problems (using 24-hour format incorrectly).

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🔴 Extended — Deep Study (3mo+)

Mirror Images — Comprehensive SSC CGL Notes

Theoretical Foundation: Plane mirror reflection follows the law of reflection from physics: the angle of incidence equals the angle of reflection. For exam purposes, the practical consequence is that objects are mirrored along the perpendicular axis to the mirror surface. When a mirror is placed vertically, the left-right axis is mirrored; when placed horizontally (above/below), the top-bottom axis is mirrored. In SSC CGL, only vertical mirrors are tested.

Complete Letter Mirror Image Reference:

Letter	Mirror Image	Notes
A	A	Vertically symmetric
B	8 or q	Reversed B
C	ɔ or reversed C	Looks like open C
D	ɔ or reversed D	Looks like open D
E	3 or reversed Ǝ	Looks like reversed 3
F	ɟ or reversed F	Looks like turned F
G	ɔ or reversed G	Looks like open G
H	H	Vertically symmetric
I	I	Vertically symmetric
J	ɾ or turned L	Looks like turned J
K	К or reversed K	Looks like backwards K
L	ɾ or turned J	Looks like turned L
M	M	Vertically symmetric
N	N or reversed N	Looks like N backwards
O	O	Vertically symmetric (circular)
P	ɡ or reversed P	Looks like open P / lowercase d
Q	ɔ or reversed Q	Looks like open Q
R	Я or reversed R	Looks like Cyrillic Я
S	Ƨ or reversed S	Changes — only rotational symmetry, not reflective
T	T	Vertically symmetric
U	U	Vertically symmetric
V	V	Vertically symmetric
W	W	Vertically symmetric
X	X	Vertically symmetric
Y	Y	Vertically symmetric
Z	reversed Z	Changes — only rotational symmetry, not reflective

Number Mirror Image Reference:

Number	Mirror Image	Notes
0	0	Symmetric in some fonts
1	1 or reversed 1	Varies by font
2	2 or reversed 2	Some fonts flip it
3	3 or Ɛ	Reversed 3 looks like E
4	4 or reversed h	Varies
5	5 or reversed 5	Some fonts flip it
6	9 or reversed 6	6 and 9 flip
7	7 or L	Some fonts look like L
8	8	Some fonts flip
9	6 or reversed 9	6 and 9 flip

Clock Mirror Formula:

• For a time H:MM (where 00:00 ≤ H:MM ≤ 11:59): Actual time = 12:00 − H:MM
• If the result is negative, add 12:00: For 1:10 → 12:00 − 1:10 = 10:50
• Special case: 11:59 in mirror shows 0:01

Examples with Full Clock Calculations:

• Mirror: 5:20 → Actual: 12:00 − 5:20 = 6:40
• Mirror: 10:15 → Actual: 12:00 − 10:15 = 1:45
• Mirror: 12:00 → Actual: 12:00 − 12:00 = 0:00 (midnight)
• Mirror: 3:45 → Actual: 12:00 − 3:45 = 8:15

Special Cases for Clocks: If the mirror is on the wall (horizontal mirror at eye level), the clock appears rotated 180° AND mirrored. However, SSC CGL always uses the standard mirror reflection formula for clock problems.

Direction-Based Mirror Problems: If a person is facing a mirror, their mirror image appears to be facing them. If person A faces east and their mirror image faces west, then in the mirror:

• East → West
• If the person raises their right hand, the mirror image appears to raise its left hand (from the person’s perspective watching the mirror).
• From the mirror image’s own perspective, it also raises its right hand — but from the viewer’s perspective (watching the mirror), it appears to raise the left.

Figure Mirror Image — Complex Cases: When a figure contains multiple elements (arrows, triangles, circles, letters):

• Each element is independently mirrored.
• The relative positions (left of, right of, above, below) are preserved.
• If triangle is to the left of circle in original, triangle is to the right of circle in mirror image.
• If square is above circle in original, square is above circle in mirror image (top-bottom preserved).

Word Mirror Problems: Find the mirror image of “EXAM”: E → Ǝ (reversed E) X → X (symmetric) A → A (symmetric) M → M (symmetric) Mirror image: ƎXAM

Find the mirror image of “SCCGL”: S → Ƨ (reversed S — it changes) C → ɔ (reversed C) C → ɔ G → ɔ (reversed G) L → ɾ (turned L) Mirror image (reading left to right, order reversed): ɾɔɔɔƧ

SSC CGL PYQ Pattern (2019-2023):

• 2023 Tier-I: 1 question — letter mirror image with non-symmetric letters
• 2022 Tier-I: 1 question — clock mirror calculation
• 2021 Tier-I: 1 question — figure mirror (geometric shape)
• Most common type: Letter sequences (3-6 letters) with mirror image options
• Clock mirror questions are asked approximately every other year
• Difficulty: Usually easy to moderate; clock calculations can be tricky

⚡ Advanced Exam Tip: When a letter sequence contains S or Z, do NOT assume they stay the same. Unlike A, H, I, M, O, T, U, V, W, X, Y — which have a true vertical line of symmetry and look identical in a mirror — the letters S and Z have only point (180°) symmetry, not reflective symmetry. So in a vertical (left-right) mirror, S becomes a reversed S (Ƨ) and Z becomes a reversed Z — they DO change. Many candidates wrongly treat S as “always S”; holding a capital S up to a mirror confirms it reads backwards. Memorise the true no-change set (A, H, I, M, O, T, U, V, W, X, Y) so you can quickly flag every other letter — including S and Z — as one that flips, eliminating wrong options in letter sequence questions.

⚡ Second Advanced Tip: For figure-based mirror questions with multiple shapes, systematically identify: (1) which shapes are on the left vs right, (2) which shapes are at the top vs bottom, (3) which shapes are pointing in which direction. Then draw the mirror image by reversing left-right positions and directions. Draw a vertical mirror line as a reference; everything to the left of the line in your image corresponds to the original’s right side.

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