On Wednesday evening at 5 PM, a student waits for a text message to arrive (hoping to arrange plans for the weekend). Each time a text arrives; the student quickly answers and then begins to wait for the next message. The student quits waiting after receiving three messages.
a. What is the sample space that describes the set of waiting times between the messages that the student receives?
b. Assume the time required to type a text response also takes a random amount of time. What is the sample space that
c. Write an expression for the event that describes the set of all waiting times and also the lengths of typing the responses as well? the waiting times get longer and longer, but the times used to type responses get shorter and shorter.