That kinda answers the question many students have whether the professors can so...

btilly · on July 7, 2020

The usual rule of thumb is that if the professor can do the test in 20 minutes, it is probably appropriate for an hour for the kids.

As a graduate student I found that to be true.

euler_angles · on July 7, 2020

Seems like a lot of people have converged around that.

I had a professor in my undergraduate mechanical engineering classes who used a 4x rule for his exams -- he had to be able to do it in 15 minutes, we had an hour.