Dot Situation and Grouping of Identical Figures: Method and Practice for SSC Non-Verbal Reasoning

In dot situation questions you are shown a figure of overlapping shapes with a dot in one region and must find the answer figure where the dot can be placed in the same kind of region. In grouping of identical figures you divide a set of figures into groups by a common property. Both are scoring non-verbal topics because they only need careful observation. This note explains the step-by-step methods, the properties used for grouping, common traps, practice questions and FAQs.

Part 1: Dot Situation

The Idea

The question figure has a dot which lies in the common region of some shapes (for example inside the circle and the square but outside the triangle). In the answer figures, you must find the one where a dot can also lie in the same combination of shapes.

Method

1. Note which shapes contain the dot in the question figure (for example circle + square, not triangle).
2. Write the combination as a code, such as C + S.
3. For each answer figure, check whether a region with the same combination exists.
4. If the region exists, a dot can be placed there, and that figure is the answer.
5. Eliminate figures where the combination cannot be formed (for example two shapes that do not overlap).

Number of Regions Formed by Overlapping Shapes

• A region common to two shapes exists only if the shapes overlap.
• A dot lying on the boundary line is usually not allowed unless the question says so.
• If the dot is in a common region of three shapes, the answer figure must have a region common to all three.
• A dot outside all shapes means the answer figure needs an empty outside region.

Part 2: Grouping of Identical Figures

The Idea

A set of figures is given. They are divided into two or three groups on the basis of a common property, and the question asks which figures belong to the same group.

Properties to Check

Method

1. Pick two figures and compare them. Find what is the same between them.
2. Test that property on all other figures to see which ones also share it.
3. If the property fails for some figures, try another property from the table.
4. Form the groups and check that every figure belongs to exactly one group.
5. Match with the options.

Common Traps

• Choosing a property that works for only part of the group; the property must apply to all the figures in a group.
• Counting lines wrongly where lines overlap or cross; mark each segment while counting.
• Ignoring the orientation when the figure is simply rotated.
• Mixing line symmetry with rotational symmetry.

Practice Tips

• Look for the simplest property first (closed or open, straight or curved) before the complex ones.
• For dot situation, sketch the figure on rough paper and write the shapes next to each region.
• Practise with figures drawn by yourself using two or three overlapping circles, squares and triangles.
• Time limit: about 30 seconds for each question.

Quick Tips

• In dot situation, convert the region into a code like C + S + T.
• Two shapes must overlap to have a common region.
• In grouping, check straight/curved lines and closed/open first.
• Count carefully; most mistakes are counting errors.

Quick Revision Points

• Two overlapping shapes give 3 regions; three overlapping shapes give 7 regions.
• A common region exists only when the shapes overlap.
• Check nature of lines, number of sides, closed or open and symmetry in grouping.
• The same property must hold for every figure in a group.
• Eliminate options step by step.

Practice Questions With Answers

1. How many regions are formed inside the union of two overlapping circles?
   Answer: 3
2. How many regions are formed inside the union of three mutually overlapping circles?
   Answer: 7
3. Can a dot lie in a region common to a circle and a square that do not overlap?
   Answer: No
4. Which property do a triangle and a square share: closed or open?
   Answer: Both are closed figures
5. A figure made of only curved lines can be grouped with a figure made of?
   Answer: Only curved lines
6. Which property tells you the number of straight segments?
   Answer: Number of lines or sides
7. If the dot lies in the common region of three shapes, the answer must have?
   Answer: A region common to all three shapes
8. Two figures differ only by rotation. Which property is likely used?
   Answer: Orientation
9. What should you do first in a grouping question?
   Answer: Compare two figures and find a common property
10. What is a closed figure?
    Answer: A figure whose boundary has no gap

How to Practise This Chapter

Practise 10 questions every day and write the steps on paper. Then attempt timed sets from our practice papers and the previous year papers page. See all topics on the Dot Situation and Grouping of Identical Figures notes page.

Frequently Asked Questions

What is a dot situation question?

A question where you find which answer figure has a region matching the one in which the dot lies in the question figure.

How do I solve dot situation questions?

Find the shapes that contain the dot, write them as a code and look for the same combination in the answer figures.

How many regions do three overlapping circles form?

Seven regions inside the union.

What is grouping of identical figures?

Dividing a set of figures into groups with a common property.

What properties are used to group figures?

Nature of lines, number of sides, closed or open, symmetry, shading and orientation.

What is the best way to find the property?

Compare two figures first and find what is common, then test it on all.

Should I count lines carefully?

Yes. Many wrong answers come from miscounting.

What is line symmetry?

A figure can be folded along a line so that both halves match.

How much time should I give each question?

About 30 seconds.

Is this topic asked in SSC?

Yes, non-verbal reasoning questions like these appear in SSC CGL, CHSL and CPO papers.

Can I practise without a book?

Yes, by drawing your own overlapping shapes and testing yourself.

What is the most common mistake?

Choosing a property that does not apply to every figure in the group.