Use a clock, a counter, and a demultiplexer to control whether a stop light is red, green or yellow. The stop light should be green for 40 seconds, followed by yellow for 10 seconds, and then red for 30 seconds, and then repeat. You can simply write by each output of the demultiplexer one of the words green, yellow, or red. Don't forget to specify how many Hz the clock needs to be