SOLUTION: *Traffic light math question At a traffic light, one cycle through green-yellow-red lasts for 80 seconds. The green light is one eight times as long as the yellow light, and the

Algebra ->  Linear-equations -> SOLUTION: *Traffic light math question At a traffic light, one cycle through green-yellow-red lasts for 80 seconds. The green light is one eight times as long as the yellow light, and the      Log On


   

Question 1123721: *Traffic light math question
At a traffic light, one cycle through green-yellow-red lasts for 80 seconds. The green light is one eight times as long as the yellow light, and the red light is on eleven times as long as the yellow light. For how long is each colored light on during one cycle?
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
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*Traffic light math question
At a traffic light, one cycle through green-yellow-red lasts for 80 seconds. The green light is one eight times as long
as the yellow light, and the red light is on eleven times as long as the yellow light. For how long is each colored light on during one cycle?
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Put your attention on how I edited your post based on common sense: 

    At a traffic light, one cycle through green-yellow-red lasts for 80 seconds. The green light is highlight%28cross%28one%29%29 eight times 
    as long as the yellow light, and the red light is highlight%28cross%28on%29%29 eleven times as long as the yellow light. 
    For how long is each colored light on during one cycle?

Solution 

If yellow light is x seconds, then the green light lasts 8x seconds and the red light lasts 11x seconds.


    x + 8x + 11x = 80

    20x = 80

    x = 80/20 = 4 seconds.


Answer.  Yellow light lasts 4 seconds; green  4*8 = 32 seconds  and  red light 11*4 = 44 seconds.