Six people are interviewing for a job Two of them are qualif

Six people are interviewing for a job. Two of them are qualified for the position. The interviewer will see them in random order and will offer the job to the first qualified candidate she interviews.

(a) Calculate the probability that the job gets offered to the second candidate.

(b) Calculate the probability that the interviewer will have to see at least three candidates before offering the job to someone.

Solution

a)

The first one is not qualified, and the second is.

Hence,

P = (4/6)*(2/5) = 4/15 [ANSWER]

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b)

That means the first two he drw are not qualified. Hence,

P = (4/6)(3/5) = 2/5 [ANSWER]