Question

A traffic light is green for 17 seconds, yellow for 3 seconds, and red for 20 seconds. Suppose your approach to the light is not affected by traffic or other factors. What is the probability that the light will be green when you first see the light? Explain.

Answer 1

 Adding all the seconds together would equal 40, and multiplying it by 2.5 will bring you to 100. So, there will be a 42.5% chance the light will be green (17x2.5 = 42.5), 50% it will be red (20x2.5 = 50), and 7.4% chance it will be yellow (3x2.5 = 7.4)