David is writing an exam consisting of 30 questions. For each question, the prob
ID: 3395761 • Letter: D
Question
David is writing an exam consisting of 30 questions. For each question, the probability that David is not sure how to do it is 0.1.
(a) It takes David 5 minutes to solve a question that he is sure and 20 minutes for a question that he is not sure. Let X be the total time that David finishes the exam. Find the expected value and variance of X.
(b) Let Y be the number of questions that David is not sure. If it takes David 5 minutes to solve a question that he is sure and (4Y 2 + 16) minutes to finish all those questions that he is not sure. Let X be the total time that David finishes the exam. Find the expected value and variance of X.
Explanation / Answer
David is writing an exam consisting of 30 questions. For each question, the prob
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.