A candidate is attempting to answer 5 multiple choice questions

with 3 possible answers each. Any wrong anwer disqualifies the

candidate automatically and the candidate is not allowed to

withdraw by himself.

If X = number of correct answers by the candidate

1. Determine the probability distribution

2. Calculate E(X) et V (X)

3. For each correct answer the candidate obtain 10 marks . Using

your ansers in (2) determine teh expected marks and its

variance.