The exclusive or means either one or the other events occurs, but not both.
a. For the formal addition rule, rewrite the formula for P(A or B) assuming that the addition rule uses the exclusive or instead of the inclusive or.
b. Repeat Exercise 11 “Fast Food Drive-Thru Accuracy” using the exclusive or instead of the inclusive or.

Data From Exercise 11:

If one order is selected, find the probability of getting an order from McDonald’s or an order that is accurate. Are the events of selecting an order from McDonald’s and selecting an accurate order disjoint events? 

Use the data in the following table, which lists drive-thru order accuracy at popular fast food chains (data from a QSR Drive-Thru Study). Assume that orders are randomly selected from those included in the table.