GATE EC 2021 Set 1 — Question 3
Go beyond PYQs with Success TrackerAI-powered personalised practice and doubt support. Unlimited practice on eligible plans; AI usage limits apply.MCQ+1 / -0.33EasyTransformation of Shapes (Translation, Rotation, Scaling, Mirroring)Spatial AptitudeGeneral Aptitude
General Aptitude → Spatial Aptitude → Transformation of Shapes (Translation, Rotation, Scaling, Mirroring)
Last updated
Question
The least number of squares that must be added so that the line P-Q becomes the line of symmetry is ________
Correct answer
(C) 6
Solution
To make the line P-Q a line of symmetry, every shaded square on one side of the line must have a corresponding shaded square at the same distance on the opposite side in the same row.Analyzing the grid row by row relative to the line P-Q:
- Row 1: There is 1 square at distance 1 to the right. We must add 1 square at distance 1 to the left.
- Row 2: There is 1 square at distance 2 to the right. We must add 1 square at distance 2 to the left.
- Row 3: There is 1 square at distance 1 to the left. We must add 1 square at distance 1 to the right.
- Row 4: There are 2 squares at distances 1 and 2 to the left. We must add 2 squares at distances 1 and 2 to the right.
- Row 5: There is 1 square at distance 1 to the left. We must add 1 square at distance 1 to the right.
Continue learning with Success Tracker
A step still unclear? Work through it with support
Use Success Tracker to ask about the reasoning, then try another GATE EC question to check your understanding.
AI-powered practice· Unlimited practice on eligible plans
- PYQs with solutions
- Attempt available previous-year questions, then compare your reasoning with the worked solution. Coverage varies by stream.
- Practice that adapts
- Choose a topic, work on weaker areas and bookmark questions to revisit. Your attempts feed your progress tracking.
- AI doubt support
- Ask follow-up questions about a step or concept while practising, instead of stopping at the final answer.
Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.
This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.
More questions on Spatial Aptitude
2026 Set 1 Q1Among the following options, the antonym of the word ‘nocturnal’ is _________.2026 Set 1 Q2The statements (S1), (S2), and (S3) pertain to the scores obtained by students in an exam. The…2026 Set 1 Q3The figure below has exactly three intersecting line segments with a rectangular portion …2026 Set 1 Q4Real numbers , , and (all greater than 1) satisfy…2026 Set 1 Q5The following observation is made about the scores obtained by 100 students in an exam: 'For each…