Answer: .3 or 3/10
Explanation: The probability that her first answer is correct is 2/5. Since she got the first guess correct, now there is only 1 correct answer out of 4. There is a 3/4 chance she will get the next problem wrong
So: 2/5 x 3/4 = .3
Mechanical problems since they can be solved and have the second most deaths. I would have the plane go through at least 3 examinations before boarding then one passenger exam before takeoff.
