Problema Solution

At a traffic light, one cycle through green-yellow-red lasts for 84 seconds. The green light is on nine times longer than the yellow light, and the red light is on eleven times longer than the yellow light. For how long is each colored light on during one cycle?

Answer provided by our tutors

Let 'g', 'y', and 'r' stand for the time that each light (green, yellow, and red, respectively) is on during one cycle. We can write:


g+y+r=84

g=9y

r=11y


Using Algebrator to solve for 'g', 'y', and 'r', we get:

g=36 s

y=4 s

r=44 s