AMC8,--,2006年真题解析



AMC8,--,2006年真题解析
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Answer: D
Solution:
The three prices round to $2 ,$5 ,and $10 ,which has a sum of 17.


AMC8,--,2006年真题解析
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Answer: C
Solution:
As the AMC 8 only rewards 1 point for each correct answer ,everything is irrelevant except the number Billy answered correctly , 13.


AMC8,--,2006年真题解析
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Answer: A
Solution:


AMC8,--,2006年真题解析
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Answer: B
Solution:
If the spinner goes clockwise 2+1/4 revolutions and then counterclockwise 3+3/4 revolutions ,it ultimately goes counterclockwise 1+1/2 which brings the spinner pointing east.


AMC8,--,2006年真题解析
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Answer: D
Solution:
Drawing segments AC and BD ,the number of triangles outside square ABCD is the same as the number of triangles inside the square. Thus areas must be equal so the area of ABCD is half the area of the larger square which is 60/2=30.


AMC8,--,2006年真题解析
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Answer: C
Solution:
If the two rectangles were seperate ,the perimeter would be 2*2*(2+4)=24. It easy to see that their connection erases 2 from each of the rectangles ,so the final perimeter is 24-2*2=20.


AMC8,--,2006年真题解析
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Answer: B
Solution:
Using the formulas of circles ,C=2*Pi*r and A=Pi*r*r ,we find that circle Y has a radius of 4 and circle Z has a radius of 3. Thus ,the order from smallest to largest radius is Z ,X ,Y.


AMC8,--,2006年真题解析


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