# Thread: Probability test Question

1. ## Probability test Question

Candidates for the graduate scheme of an oil major have to take two tests prior to interview, a psychometric test and an aptitude test. The results based on previous applicants show that P (Candidate passes psychometric test) = 0.8 and P(candidate passes aptitude test) = 0.3
Assume that performance on one test is independent of the other.

1. When a candidates applies for the post what is the probability he or she passes both tests?

2. When a candidates applies for the post what is the probability he or she passes just one of the tests?

3. Ambitious, but incompetent candidate applies for the post repeatedly. What is the probability that he or she passes the psychometric test after 5 attempts.

Please me out on this one with working out.

Thank You

2. Originally Posted by JJC85
Candidates for the graduate scheme of an oil major have to take two tests prior to interview, a psychometric test and an aptitude test. The results based on previous applicants show that P (Candidate passes psychometric test) = 0.8 and P(candidate passes aptitude test) = 0.3
Assume that performance on one test is independent of the other.

1. When a candidates applies for the post what is the probability he or she passes both tests?

2. When a candidates applies for the post what is the probability he or she passes just one of the tests?

3. Ambitious, but incompetent candidate applies for the post repeatedly. What is the probability that he or she passes the psychometric test after 5 attempts.

Please me out on this one with working out.

Thank You
You need to review the basic probability formulae. Your job is to explain the following:

1. (0.8)(0.3) = ....

2. (0.8)(0.7) + (0.2)(0.3) = ....

3. (0.2)^4 (0.8) = ....