Difference between revisions of "2007 AMC 10B Problems/Problem 25"

(New page: How many pairs of positive integers (a,b) are there such that a and b have no common factors greater than 1 and: <math>\mathrm frac {a}/{b}</math> + <math>\mathrm frac {14b}/{9a}</math> ...)
 
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How many pairs of positive integers (a,b) are there such that a and b have no common factors greater than 1 and:
 
How many pairs of positive integers (a,b) are there such that a and b have no common factors greater than 1 and:
  
<math>\mathrm frac {a}/{b}</math> + <math>\mathrm frac {14b}/{9a}</math>  
+
<math>\frac{a}{b} + \frac{14b}{9a}</math>  
  
 
is an integer?
 
is an integer?

Revision as of 19:48, 1 January 2010

How many pairs of positive integers (a,b) are there such that a and b have no common factors greater than 1 and:

$\frac{a}{b} + \frac{14b}{9a}$

is an integer?

(A) 4

(B) 6

(C) 9

(D) 12

(E) infinitely many