The mathematics faculty at a college consists of 11 professo

The mathematics faculty at a college consists of 11 professors, 6 associate professors, 11 assistant professors, and 12 instructors. If one faculty member is randomly selected, find the probability of choosing a professor or an instructor.

Solution

P(A) = probability of selecting a professor

total number of faculty = 11+6+11+12=40

we have 11 professors and choosing one from \'40\'

P(A) =11/40

P(B) = probability of selecting a instructor

we have 12 instructors so choosing one from \'40\'

P(B) = 12/40

now we have to

P( A or B) = P(A) +P(B)

   =11/40 +12/40

   = 23/40