Problem 2 · 2024 Math Kangaroo
Easy
Geometry & Measurement
gridcareful-counting
Five pencils labelled A, B, C, D and E lie on a grid of lines. Which pencil is the longest?
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Answer: D — D
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Hint 1 of 3
The straight lines in the background are spaced evenly, like the marks on a ruler.
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Hint 2 of 3
For each pencil, count how many spaces it covers from its flat back end to its pointy tip.
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Hint 3 of 3
The pencil that crosses the most spaces is the longest one.
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Approach: use the evenly spaced lines like a ruler
- The background lines are all the same distance apart, so we can count spaces to compare lengths.
- Count the spaces each pencil covers from its back end to its tip; pencil D reaches across more spaces than any other.
- So pencil D is the longest.
Mark:
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