Two interesting questions

Hello,

I would like to ask you two interesting questions, really am not sure how to answer if being asked in an interview?

1.) Sitting on the side of the road you observe that at least one car drive by every 20 minutes. What is the probability to see exactly one car in 5 minutes ?

2.) Here's a maze I drew while interviewing another candidate. What quantitative characteristics of this maze would you use to qualitatively decide on the difficulty of a maze?

For the first, it looks, at least to me, like insufficient data, and I really don't know how to approach him.

For the second, firstly I would look how many open entrances are in a maze, so that would suggest me sth. about the whole difficulty. Afterwards, I would divide maze in smaller intervals uniformly (for example 3 intervals, then 5, etc...) and check the same thing for them, is it possible to pass first third of a maze, then second third and so on.. Does this seem to you like a logical reasoning, I am almost sure that there are better ideas how to solve this one...