The city of Washington, D. allows for two-hour parking near the National Mall. Parking ocials regularly tour around, passing the same spot every two...

The city of Washington, D.C. allows for two-hour parking near the National Mall.

Parking ocials regularly tour around, passing the same spot every two hours.

Whan an ocial encounters a car he or she marks it with chalk. If the same car

is there on the ocial's return two hours later, then a parking ticket is written.

Suppose you park near the mall, and your parking time is exponentially distributed

with parameter lambda (mean = 1/lambda) and is independent of the time that you park.

What is the probability that you will receive a parking ticket? Sketch a graph of

your solution (as a function of lambda).