Answer:
The probability that they will teach different courses is
.
Step-by-step explanation:
Sample space is a set of all possible outcomes of an experiment.
In this case we will write the sample space in the form (x, y).
Here <em>x</em> represents the course taught by the first part-time instructor and <em>y</em> represents the course taught by the second part-time instructor.
Denote every course by their first letter.
The sample space is as follows:
S = {(P, P), (P, I), (P, S), (I, P), (I, I), (I, S), (S, P), (S, I) and (S, S)}
The outcomes where the the instructors will teach different courses are:
s = {(P, I), (P, S), (I, P),(I, S), (S, P) and (S, I)}
The probability of an events <em>E</em> is the ratio of the number of favorable outcomes to the total number of outcomes.

Compute the probability that they will teach different courses as follows:

Thus, the probability that they will teach different courses is
.