Question

Giving a test to a group of students, the grades and gender are summarized below A B C Total Male 18 2 15 35 Female 20 12 19 51 Total 38 14 34 86 If one student is chosen at random, Find the probability that the student did NOT get an "B"

Answer 1

If we are choosing students at random from all students who got a B:

Total number of non-female students who got a B: 19

Total number of students who got a B: 36

Probability: 19/36

If we are choosing students at random from all students:

Total number of non-female students who got a B: 19

Total number of students: 78

Probability: 19/78