Difference between revisions of "2002 AMC 12P Problems/Problem 6"

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== Problem ==
 
== Problem ==
How many positive [[integer]]s <math>b</math> have the property that <math>\log_{b} 729</math> is a positive integer?
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Participation in the local soccer league this year is <math>10</math>% higher than last year. The number of males increased by <math>5</math>% and the number of females increased by <math>20</math>%. What fraction of the soccer league is now female?
  
<math> \mathrm{(A) \ 0 } \qquad \mathrm{(B) \ 1 } \qquad \mathrm{(C) \ 2 } \qquad \mathrm{(D) \ 3 } \qquad \mathrm{(E) \ 4 } </math>
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<math>
 +
\text{(A) }\frac{1}{3}
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\qquad
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\text{(B) }\frac{4}{11}
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\qquad
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\text{(C) }\frac{2}{5}
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\qquad
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\text{(D) }\frac{4}{9}
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\qquad
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\text{(E) }\frac{1}{2}
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</math>
  
 
== Solution ==
 
== Solution ==

Revision as of 23:44, 29 December 2023

Problem

Participation in the local soccer league this year is $10$% higher than last year. The number of males increased by $5$% and the number of females increased by $20$%. What fraction of the soccer league is now female?

$\text{(A) }\frac{1}{3} \qquad \text{(B) }\frac{4}{11} \qquad \text{(C) }\frac{2}{5} \qquad \text{(D) }\frac{4}{9} \qquad \text{(E) }\frac{1}{2}$

Solution

If $\log_{b} 729 = n$, then $b^n = 729$. Since $729 = 3^6$, $b$ must be $3$ to some factor of 6. Thus, there are four (3, 9, 27, 729) possible values of $b \Longrightarrow \boxed{\mathrm{E}}$.

See also

2002 AMC 12P (ProblemsAnswer KeyResources)
Preceded by
Problem 5
Followed by
Problem 7
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions

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