"Time headway" in trafc flow is the elapsed time between the time that one car nishes passing a xed point and the instant that the next car begins to pass that point. Let x = the time headway for two randomly chosen consecutive cars on a freeway during a period of heavy ow. The following probability density function (pdf) of x is I] A -'15(x- 0-5) 20.5 f(X) =n e X ' I] 0 otherWISE a) Find the value of A. b) What is the probability that the time headway is at most 6 seconds