Solved IB ACIO Question
A solved IB ACIO PYQ — decoded step-by-step.
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Q · Counting of Figuresmedium · 45s
A figure consists of 3 horizontal and 3 vertical lines forming a grid of small squares. How many squares are there in total?
TopicCounting of Figures
Question Typemultiple choice
Difficultymedium
Marking+1 / −0.25
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
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The number of squares in a grid = 1² + 2² + 3² + ... + (n-1)² - 3 lines create 2 × 2 small squares, so total squares = 1² + 2² = 1 + 4 = 5 (small squares) - But 3 vertical & 3 horizontal lines create 4 × 4 grid of squares in total, so count all sizes: 1² + 2² + 3² = 1 + 4 + 9 = 14 total squares (revised) - Considering confusion, the correct total is 4 squares of size 1×1, plus 1 of 2×2, total 5, so in 3×3 squares number will be 9
Final Answer: Option D — 16