You arrive to a trolly stop, just missing the last trolly. The time until the next rolly arrival is modeled as a U(4,6) random variable. You decide that you will walk to your destination (and not use the trolly) if the next trolly takes longer than 5 minutes to arrive. Let random variable X be the amount of time you spend at the trolly stop.
a) Find P(X<=4.5)
b) Find P(X=5)
2) Let Y~ Exp (1/5). Find P(Y<=18/Y>13)