word problem

Question

At a traffic light, one cycle through green-yellow-red lasts for 76 seconds. The green light is on seven 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 1

Let x = the length of time the yellow light is on

Let 7x = the length of time the green light is on

Let 11x = the length of time the red light is on

 

x + 7x + 11x = 76

19x = 76

x = 4 seconds

7x = 28 seconds

11x = 44 seconds