Difference between revisions of "1983 USAMO Problems/Problem 1"

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If six points are chosen sequentially at random on the circumference of a circle, what is the probability that the triangle formed by the first three is disjoint from that formed by the second three.
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==Problem==
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If six points are chosen sequentially at random on the circumference of a circle, what is the probability that the triangle formed by the first three is disjoint from that formed by the second three?
  
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==Hint==
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First choose six points on the circumference on a circle. What is the probability that selecting three random points will yield a triangle that is disjoint from the triangle formed by the other three points?
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==Solution==
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The probability in the hint equals <math>\frac{3}{10}</math>, and that is the answer!
 
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Revision as of 15:28, 19 April 2014

Problem

If six points are chosen sequentially at random on the circumference of a circle, what is the probability that the triangle formed by the first three is disjoint from that formed by the second three?

Hint

First choose six points on the circumference on a circle. What is the probability that selecting three random points will yield a triangle that is disjoint from the triangle formed by the other three points?



Solution

The probability in the hint equals $\frac{3}{10}$, and that is the answer! The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png