Question

A physics class has 40 students. Of these,14 students are physics majors and 18 students are female. Of the physics majors, six are female. Find the probability that a randomly selected student is female or a physics major.

The probability that a randomly selected student is female or a physics major is___. (Round to 3 decimal places)

Answer 1

P(Student selected is Physics Major) = 14/40 = 0.350

P(Student selected is Female) = 18/40 = 0.450

P(Student selected is Physics Major AND Feamle) = 6/40 = 0.150

P(A OR B) = P(A) + P(B) ? P(A ? B)

Using same formula:

P(Student selected is Physics Major OR Female) =  P(Student selected is Physics Major) + P(Student selected is Female) - P(Student selected is Physics Major or Feamle)

P(Student selected is Physics Major OR Female) = 0.450 + 0.350 - 0.150

P(Student selected is Physics Major OR Female) = 0.650