Difference between revisions of "2015 AMC 12B Problems/Problem 7"

(Problem)
(Problem)
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A regular 15-gon has <math>L</math> lines of symmetry, and the smallest positive angle for which it has rotational symmetry is <math>R</math> degrees. What is <math>L+R</math> ?
 
A regular 15-gon has <math>L</math> lines of symmetry, and the smallest positive angle for which it has rotational symmetry is <math>R</math> degrees. What is <math>L+R</math> ?
  
<math>\textbf{(A)}\; ? \qquad\textbf{(B)}\; ? \qquad\textbf{(C)}\; ? \qquad\textbf{(D)}\; ? \qquad\textbf{(E)}\; ?</math>
+
<math>\textbf{(A)}\; 24 \qquad\textbf{(B)}\; 27 \qquad\textbf{(C)}\; 32 \qquad\textbf{(D)}\; 39 \qquad\textbf{(E)}\; 54</math>
  
 
==Solution==
 
==Solution==

Revision as of 23:11, 3 March 2015

Problem

A regular 15-gon has $L$ lines of symmetry, and the smallest positive angle for which it has rotational symmetry is $R$ degrees. What is $L+R$ ?

$\textbf{(A)}\; 24 \qquad\textbf{(B)}\; 27 \qquad\textbf{(C)}\; 32 \qquad\textbf{(D)}\; 39 \qquad\textbf{(E)}\; 54$

Solution

See Also

2015 AMC 12B (ProblemsAnswer KeyResources)
Preceded by
Problem 6
Followed by
Problem 8
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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