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1999 AMC 8 Question 10

AMC8 · 1999 AMC 8

Question 10

A complete cycle of a traffic light takes $60$ seconds. During each cycle the light is green for $25$ seconds, yellow for $5$ seconds, and red for $30$ seconds. At a randomly chosen time, what is the probability that the light will NOT be green?
  1. $\dfrac{1}{4}$
  2. $\dfrac{1}{3}$
  3. $\dfrac{5}{12}$
  4. $\dfrac{1}{2}$
  5. $\dfrac{7}{12}$