Problem 10 · 2021 Math Kangaroo
Medium
Geometry & Measurement
path-tracing
Rose the cat walks along the wall. She starts at point B and follows the direction of the arrows shown in the picture. The cat walks a total of 20 metres. Where does she end up?
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Answer: D — D
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Hint 1 of 3
Follow the arrows and add up the side lengths as the cat walks.
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Hint 2 of 3
Notice that one full loop brings her all the way back to where she started.
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Hint 3 of 3
After one full loop she still has a little walking left, so keep going from B.
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Approach: walk the path and keep a running total
- Following the arrows from B, the sides are 4, 1, 5, 2 and 3 metres, which add to 15 m for one full loop back to B.
- After 15 m she is at B again, with 20 − 15 = 5 m left to walk.
- B to C is 4 m and C to D is 1 m, using the last 5 m exactly.
- So she ends at D.
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