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Problems
Contests
National and Regional Contests
USA Contests
MAA AMC
AMC 12/AHSME
1957 AMC 12/AHSME
20
20
Part of
1957 AMC 12/AHSME
Problems
(1)
Trip by Automobile
Source:
6/8/2009
A man makes a trip by automobile at an average speed of
50
50
50
mph. He returns over the same route at an average speed of
45
45
45
mph. His average speed for the entire trip is:
<
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47
7
19
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B
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47
1
4
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C
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47
1
2
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D
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47
11
19
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E
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none of these
<span class='latex-bold'>(A)</span>\ 47\frac{7}{19}\qquad <span class='latex-bold'>(B)</span>\ 47\frac{1}{4}\qquad <span class='latex-bold'>(C)</span>\ 47\frac{1}{2}\qquad <span class='latex-bold'>(D)</span>\ 47\frac{11}{19}\qquad <span class='latex-bold'>(E)</span>\ \text{none of these}
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47
19
7
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B
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47
4
1
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C
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47
2
1
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D
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47
19
11
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E
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none of these
MATHCOUNTS