Problem 3 · 2016 Math Kangaroo
Easy
Spatial & Visual Reasoning
paper-cutting
A 10 cm long piece of wire is folded so that every part is equally long (see diagram). The wire is then cut through in the two marked positions. How long are the three pieces created in this way?
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Answer: A — 2 cm, 3 cm, 5 cm
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Hint 1 of 3
The wire is folded into equal little segments, so each segment is the same length.
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Hint 2 of 3
Imagine unfolding the wire into one straight 10 cm line and mark where the two cuts land.
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Hint 3 of 3
Count how many equal segments fall in each of the three pieces.
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Approach: unfold the wire and read off the cut positions
- Folding 10 cm into equal parts makes a row of equal-length segments.
- If you straighten the wire back out, the two marked cuts land on segment boundaries.
- Counting the segments in each piece gives lengths of 2 cm, 3 cm and 5 cm (which add back to 10 cm), choice (A).
Mark:
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