Hello,

I haven't looked at the other questions yet, but the first one is false

You're working with a probability density function. The probability of getting a value equal to 3, while working with a rv with pdf, is 0.a) i substituted in z=3 hence my answer was 0.112

What you're asked is the probability that the man fails to do it in 3 minutes. Which means it's the probability that it takesmorethan 3 minutes to do the task.

So you're looking for P(Z>3), which is , and not

I guess you made the same mistake for question b)