Query on probability and statistics:ignou mcom

the traffic light at a certain road crossing is set in the following fashion. It starts green at 06:00 and continues to be green till 6:02 and again turns green at 6:06 and continues green till 6:08.This cycle is repeated throughout the day.What percentage of the item during any given hour, traffic light will be green?

If your arrival time at this crossing is random and uniform over the interval 16:55 to 17:05, what is the PROBABILITY THAT U WILL HAVE TO STOP AT THIS LIGHT.
(ignou mcom:20 marks)