SOLUTION: A traffic light is red for 25 seconds, yellow for 5 seconds, and green for 55 seconds. What is the probability that when you reach the light, the light is not green?

Algebra ->  Probability-and-statistics -> SOLUTION: A traffic light is red for 25 seconds, yellow for 5 seconds, and green for 55 seconds. What is the probability that when you reach the light, the light is not green?      Log On


   

Question 484322: A traffic light is red for 25 seconds, yellow for 5 seconds, and green for 55 seconds. What is the probability that when you reach the light, the light is not green?
Answer by kingme18(98) About Me  (Show Source):
You can put this solution on YOUR website!
Probability = (number of events that meet the requirements) / (total number of events)

Here, the probability will be (number of seconds that meet the requirements)/(number of total seconds). The numerator is the number of seconds that meet the requirement of NOT GREEN. That happens when the light is red or yellow: 25 + 5 = 30 seconds. The total number of seconds in a given rotation between green, yellow, and red is 25 + 5 + 55 = 85 seconds. That is our total number of seconds, and will be the denominator.

So, our probability is 30%2F85, which reduces to 6%2F17 or about 0.35.