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Starting in West direction: 1 green light means 20 km/hr

So 15 minutes at 20km/hr, means covers 15/60 * 20 = 5 km

Next, 2 red & 2 green lights, means turn left and 24 minutes at 40 km/hr

So now distance covered = 24/60 * 40 = 16 km

Now for next 45 minutes, 1 red & 3 green lights, means turned right and drove at 60 km/hr, so covered 45/60 * 60 = 45 Km

Next – 1 red & 2 green lights, turned right and 18 minutes at 40 km/hr

So covered = 18/60 * 40 = 12 km. Next 3 red lights so stopped

So total distance = 5+16+45+12 = 78 km