Problem 8 · 2015 Math Kangaroo
Easy
Spatial & Visual Reasoning
spatial-reasoning
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Answer: C
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Hint 1 of 2
Within 5 m of the tree is a disk; at least 5 m from the kennel removes a disk around the kennel.
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Hint 2 of 2
Draw the full disk around the tree, then cut out the part closer than 5 m to the kennel.
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Approach: intersect a disk with the outside of another disk
- Staying within 5 m of the tree gives a filled disk of radius 5 centred on the tree.
- Staying at least 5 m from the kennel removes a 5 m disk around the kennel from that region.
- The result is the tree's disk with a circular bite taken out on the kennel side.
- The matching picture is C.
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