A car has to go through 15 unsynchronized traffic lights
separated by a long distance. The Traffic lights are numbered {1,
2, .., 15} and the car goes through them in that order.
Assume that the probability of stopping at any of those lights is
63%.
a) Find the probability that you have your second stop
either at or before traffic light # 6 is
b) Let X = the total number of traffic lights you have to stop,
then Pr (7< X<= 10) =