Mirror Images - General Intelligence and Reasoning for SSC CGL PDF Download

Introduction

The image of an object produced by a mirror is called its mirror image or mirror reflection. In a mirror image the left and right sides of the object are interchanged: what is on the right of the original appears on the left in the mirror image and vice versa. This phenomenon is known as lateral inversion.

Some characters remain unchanged when viewed in a mirror because they possess vertical (bilateral) symmetry. The uppercase letters that are identical to their mirror images are A, H, I, M, O, T, U, V, W, X, Y. In lower case, the letters i, l, o, v, w, x retain the same appearance in a mirror (depending on the font style used in the question paper). According to standard reasoning-test conventions, the digits 1 and 8 are also considered identical to their mirror images.

An object that can be split into two congruent halves by a vertical line (a line drawn from top to bottom) is said to have bilateral symmetry. Such an object produces a mirror image that is identical to the original object when the mirror is placed vertically.

Working Rule for Mirror Images

To understand mirror images, remember these basic points.

From the figure above it is clear that:

• Top and bottom remain unchanged when a vertical mirror is used.
• Left and right are interchanged: the left-hand side (LHS) of the original becomes the right-hand side (RHS) in the mirror image, and the RHS becomes the LHS.

Types of Mirror-Image Questions

• Letter / Number Image Questions: A combination of letters, words or numbers is given; you must identify the correct mirror image from the alternatives.
• Geometrical Image Questions: Figures composed of geometric shapes are shown; you must determine which option is the correct mirror image or which figures remain unchanged under reflection.

How to Solve Mirror-Image Problems

Use the following practical rules and checks when solving mirror-image questions:

1. Visualise or imagine a vertical mirror placed immediately in front of the object. The mirror lies along a vertical plane in front of the figure.
2. Exchange left and right while keeping top and bottom unchanged. Mentally swap positions of elements on the left with those on the right.
3. Check for vertical symmetry: if an object is symmetric about a vertical line, its mirror image will be identical to the original.
4. Use a quick paper-fold test: fold an imaginary vertical line through the figure; if the two halves coincide exactly, the figure is unchanged on reflection.
5. In multiple-component figures, track distinctive marks (dots, arrows, ticks) to verify their swapped positions in the mirror image.
6. Be careful with fonts and stylisation: some letters or digits may look symmetric in one font but not in another; rely on commonly used printed shapes unless the question specifies otherwise.

Practical Tips and Common Pitfalls

• Do not confuse mirror reflection with rotation. A mirror image is not a rotated copy; it is a lateral (left-right) reversal.
• If the mirror is horizontal (placed above or below), top and bottom will interchange while left and right remain the same. Most reasoning tests use vertical mirrors unless stated otherwise-read the question carefully.
• When letters are combined into words, the whole word reads reversed left-to-right in the mirror; individual letters that are not symmetric will appear reversed.
• When several figures are arranged in a row, treat each part's left-right positions relative to the whole arrangement rather than separately unless the question instructs otherwise.
• For geometrical patterns, mark one or two key points and follow their new positions after reflection; this reduces errors in complex figures.

Examples and Short Practice

Example 1: Which of the following uppercase letters will remain identical after reflection in a vertical mirror?

Answer: A, H, I, M, O, T, U, V, W, X, Y.

Example 2: Which lower-case letters commonly remain identical after a vertical mirror reflection?

Answer: i, l, o, v, w, x.

Example 3: Digits identical to their mirror images (standard convention used in reasoning papers)

Answer: 1 and 8.

Short Method Checklist for Quick Answers

• Imagine vertical mirror → swap left and right; top and bottom unchanged.
• Check vertical symmetry (folding test) to see if figure remains same.
• Follow distinctive marks to verify new positions after reflection.
• Watch for question wording: mirror orientation (vertical/horizontal) and font style may affect answers.

Summary

Mirror images result from lateral inversion: left and right are interchanged while top and bottom remain the same under a vertical mirror. Characters and figures with vertical (bilateral) symmetry remain unchanged. Apply a visual fold test, track distinctive elements, and confirm whether the mirror is vertical or horizontal to solve questions correctly.