The mathematics faculty at a college consists of 4 professors, 5 associate professors, 6 assistant professors, and 8 instructors. If one faculty member is randomly selected, find the probability of choosing a professor or an instructor.

There are a total of 4+5+6+8 = 23 faculty members.

the probability of selecting a professor (4) or an instructor (8) is:

(4+8) / 23 = > 12/23 = > 0.54 or 54%

First you add everyone together.

8+6+5+4=23

since there are 5 associate professors and 8 instructors you add them together.

4+8=12

you divide the number of professors and instructors by the number of everyone.

12/23=.52

you move the decimal over 1 place and there's your answer.

52%